Making an air pressure powered drinks dispenser is easier than it looks, and a fantastic hands-on air pressure demonstration.

What is air pressure?

Air and its particles are crashing into us all the time. What we call air pressure is the force of these particles hitting a surface.

When you suck a straw you reduce the pressure inside the straw, making the pressure outside the straw acting on the liquid greater than the pressure inside the straw. This pushes the liquid up the straw, allowing you to drink it!

Drinks Dispenser Air Pressure Demonstration

You'll need

Balloon

Peg - optional, but helpful

Plastic bottle - I used a 750ml bottle

Plasticine or putty

Plastic Straw

Water

Small container

How to make an air pressure drinks dispenser

Carefully make a small hole about halfway up the bottle and push the straw through, leaving ⅓ to ½ on the outside.

Fill the bottle about three-quarters full of water.

Blow up the balloon, twist and seal the neck with a peg. Carefully place the end of the balloon on the bottle neck and place a glass under the straw.

When you're ready, remove the peg and watch as the water shoots out of the straw into the glass!

Be careful, as it might shoot out further than you expect.

Why does this happen?

Air presses down equally on the water in the bottle and in the straw when no balloon is present ( or the balloon is pegged ), but when the peg is removed, air from the balloon increases the air pressure in the bottle, pushing down on the water, forcing it through the straw.

More Air Pressure Experiments

Air pressure is a great concept to explore as it causes lots of fun effects.

Demonstrate the Bernoulli Principle with a very simple demonstration using a plastic bottle and a ball of paper.

Suck a boiled egg into a jar without touching it.

Build and launch a bottle rocket!

The post Air Pressure Demonstration - DIY Drinks Dispenser appeared first on Science Experiments for Kids.

This activity uses Skittles to demonstrate radioactive decay. The rate of decay depends on the isotope of the element and is referred to as the half-life. Radioactive decay is a random process.

To understand the concept of a half-life, we're going to pretend Skittles are radioactive atoms. Skittles that land with the S upwards are radioactive, and those that land with the S down are decayed and are no longer radioactive.

Skittles Half-Life Demonstration

You'll need

Skittles

Pen and Paper

Instructions

Count the total number of Skittles and record this in the first column of the table.

Put the Skittles back in the bag and shake it for about 10 seconds. This represents a half-life. Pour the Skittles out and remove any that landed with the 'S' downwards. These have decayed.

Count the number of Skittles left and record the amount in the table. These are still radioactive. Put them back in the bag and shake for another ten seconds. This represents a second half-life.

Remove the Skittles with S down, and count the number left.

Repeat until there are no more Skittles left.

Radiation and Activity - Key points

Radioactive sources contain radioactive isotopes that release radiation from the nuclei of their atoms.

The radioactivity of a source decreases over time. This can be a few hours or millions of years, depending on the isotope.

Radioactivity is a random process. You can't predict which unstable nuclei in a sample of radioactive material will decay next.

In a sample with lots of nuclei, scientists can predict how many will decay in a given time based on the half-life of the source material.

The rate at which a source decays is called its activity.

Activity is measured in becquerels, Bq. 1 Bq is 1 decay per second.

Radioactive activity is measured with a Geiger-Müller tube, which clicks every time it detects radiation.

Half-Life

Half-life is the average time taken for the number of radioactive nuclei of an isotope to halve.

What does a short half-life mean?

A short half-life means the activity drops quickly as the nuclei are very unstable and decay rapidly.

Radioactive sources with a short half-life are dangerous as they emit a high amount of radiation at the beginning but quickly become safe.

What does a long half-life mean?

A long half-life means radioactive activity falls slowly. The source releases small amounts of radiation over a long period of time.

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A singing balloon experiment is a great way to learn how sound works. If you put a small coin inside a balloon and spin it, the coin spins around the balloon, making the balloon vibrate very quickly. Objects that vibrate quickly make a high pitched sound. As the coin slows down, the pitch of the sound gets lower. Children can hear how the sound changes as the coin slows inside the balloon.

Singing balloon sound and pitch investigation

You'll need

A balloon

Small coin

Instructions

Stretch the neck of the balloon and carefully put the coin inside.

Blow up the balloon ( ask an adult to help ).

Fasten the end of the balloon so the air cannot escape.

Hold the balloon at the top and carefully spin it in circles. Take care when doing this, as if the balloon bursts, the coin will fly out at high speed.

Listen to the sound the balloon and coin make.

You should find the pitch drops as the coin slows down.

What's happening?

When the coin spins fast, the balloon vibrates quickly, creating a high-pitched sound. As the coin slows, the balloon vibrates less, and the pitch drops.

More science experiments for learning about sound

Find out how you can see sound using rice and a drum.

Make a straw flute with straws and tape! The pitch of the sound changes with the length of the straw.

Test different materials to find out which are the best for muffling sound.

The post Singing Balloon Experiment appeared first on Science Experiments for Kids.

You've probably seen lightning flash across the sky, but do you know why and how it happens? This simple science activity teaches how lightning forms and how to make a small spark using static electricity.

What is lightning?

Lightning is a giant spark of electricity in the atmosphere. It happens when electricity is discharged between clouds, from a cloud to air or from a cloud to the ground.

Clouds contain lots of water droplets, ice crystals, and tiny hailstones moving around. When they bump into each other, they create an electric charge. After a period of time, the cloud becomes full of electrical charges. The top becomes positively charged, and the bottom becomes negatively charged.

As negative charge builds at the bottom of the cloud, electrons near the ground's surface are repelled, leaving the ground with a positive charge. When the attraction between the cloud and the ground is enough, the charge from the cloud discharges and electrons shoot down from the cloud to the ground.

Make Lightning

You'll need

Balloon

Metal spoon

Hair or a woolly jumper

A dark room

Instructions

Blow up the balloon and tie the end.

Hold the balloon with the tie and rub it on your hair or a woolly jumper.

Hold the spoon with your other hand and slowly move it towards the balloon.

You should see a tiny spark of static electricity jump from the balloon to the metal spoon.

What's happening?

When you rub the balloon on your hair, it becomes positively charged. When the metal spoon is held close to the balloon, the negative charge on the spoon connects to the positive charge on the balloon and creates the tiny spark of "lightning" you see.

This is similar to what happens in clouds.

The metal spoon is a conductor, which means electricity can travel through it.

Another way to make lightning is with an aluminium pie pan and a pencil!

Lightning Facts

Lightning is VERY hot! It can be 5 times hotter than the surface of the sun.

Lightning strikes Earth about 100 times every second!

Lake Maracaibo in Venezuela is known as the most lighting prone place on Earth.

If lightning strikes sand, it can turn it into a glass like structure called fulgurite.

Can you get thunder without lightning?

Thunder happens because of lightning, so you can't get thunder without lightning, but you might see lightning and not hear thunder.

What is thunder?

Lightning causes rapid heating of the air around it, which expands very quickly, creating a shock wave that travels outwards. This is what we hear as thunder!

When the sound waves reach our ears, we hear them as a very loud boom noise.

Why is lightning before thunder?

Light waves travel faster than sound waves, so we see the lightning flash before we hear the thunder!

How can you tell how far away lightning is?

Count the time between seeing the lightning flash and hearing the thunder. Every 5 seconds is about a mile!

Remember to stay safe during thunderstorms. It's best to stay indoors if you hear thunder!

The post Make Lightning with a Balloon and Spoon appeared first on Science Experiments for Kids.

There are lots of great air pressure demonstrations around, but a leaky water bottle is one of the simplest. It looks impressive and costs almost nothing.

Air is made up of several different gases. Air pressure is caused by gravity pulling air molecules towards Earth. We don't really notice air pressure as it's balanced inside and outside of our body.

The weight of air ( and air pressure ) decreases with altitude. At sea level, air pressure is high. At the top of a mountain, air pressure is lower as there's less atmosphere to push down. We don't feel the pressure as it is exerted equally in all directions, but we can sense a sudden change in pressure, like when taking off or descending in a plane.

Leaky Water Bottle Demonstration

You'll need

An empty water bottle with a lid

Needle, nail or paperclip

Water

Food colouring - optional

Sink or tray

Instructions

Carefully use the needle or paperclip to poke a small hole on each side of the bottle about one-third of the way up from the bottom. Ask an adult to help

Place the bottle in a sink and fill with water. Quickly put the lid in place.

Open the lid, and the bottle should start to leak through the holes.

Close the lid, and the water will stop flowing.

With the lid on tightly squeeze the bottle, water should flow out of the holes as squeezing increases the pressure inside the bottle.

Carefully poke a needle into the bottle above the water line - ask an adult to help. When the needle is in place, blocking the hole, water will not flow out. When the needle is removed, it will start to flow again.

Why does it work?

When the lid is unscrewed, water flows from the holes in the side, reducing the volume of water in the bottle. Air rushes in through the loose lid to replace the lost water.

When the lid is tightened, air can no longer rush in to replace the water, so any water leaving the bottle reduces the pressure inside, which stops the water escaping.

Extension Challenge

With the cap slightly unscrewed, drop the bottle to the floor. Watch what happens to the flow of water.

Try one of my other easy air pressure experiments.

Air pressure fun facts

A barometer is used to measure air pressure.

Atmospheric pressure drops with altitude.

Atmospheric pressure is an indicator of weather. Low pressure leads to clouds, wind and precipitation. High pressure usually results in clear skies and fine weather.

The Earth's atmosphere is approximately 78% nitrogen.

Why do your ears pop in an aeroplane?

Ears pop in an aeroplane as your ears try to equalise the pressure. When a plane takes off, the atmospheric pressure decreases, and as you come down, it increases again.

The post Leaky bottle Air Pressure Demonstration appeared first on Science Experiments for Kids.

A stacked ball drop demonstration is a brilliant way to demonstrate momentum transfer between objects. The compression of the bigger two balls bounces the smallest ball much higher than it would normally bounce.

You'll need

A basketball

A tennis ball or small basketball/football

Table tennis ball or golf ball

Stacked Three Ball Drop Instructions

Hold your arms outstretched and drop the smallest ball. Watch how high it bounces.

Place the tennis ball on top of the basketball, drop them both, and watch what happens.

Stack the three balls on top of each other, with the smallest at the top. Try to hold them straight. Let them drop and watch what happens.

What's happening?

When held in the air each ball has an amount of potential energy. When the ball hits the ground, it compresses.

When the basketball hits the ground, it compresses slightly, storing potential energy. When the ball starts to leave the ground, the energy is released to the smaller tennis ball, which allows it to bounce higher than it would without the basketball. The basketball transfers its higher momentum ( from its greater mass ) to the smaller ball.

You'll notice the bigger balls bounce less than expected as they have lost energy to the smaller balls.

More science experiments using balls

Find out why balls bounce with a simple science investigation.

Try a ball drop gravity race.

Science Concepts

Energy

Potential energy

Momentum

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If you were to drop a table tennis ball and a basketball, which do you think would hit the ground first? This sporty science activity is an eye-opening demonstration with lots of opportunities for learning and exploration.

Sporty Science Ball Drop Investigation

You'll need

4 different balls - for example, table tennis ball, golf ball, football, basketball, tennis ball.

An empty space

Instructions

Choose two balls and think about which you think will hit the ground first.

Hold the balls at the same height and drop them.

Which hits the ground first? Was it the one you expected?

Try again with two more balls.

What's going on?

The balls should hit the ground roughly at the same time. This is because the force of gravity acting on both balls is the same. This means when they leave your hand, they accelerate at the same rate even though their mass is different.

Did you spot that I said "roughly at the same time"? On Earth there is also air resistance to consider. If you were to drop a piece of paper and a ball, the air resistance acting on the paper would be greater than that acting on the ball, so the paper would fall to the ground more slowly. In our example, with two balls at a short height, the effect of air resistance isn't enough to make a visible difference as they fall.

The post Ball Drop Gravity Race appeared first on Science Experiments for Kids.

The colour of an object is the colour it reflects, while other colours are absorbed. White reflects all the colours of the spectrum, while black absorbs all the colours, reflecting very little back.

Visible white light from the sun consists of seven colours: red, orange, yellow, green, blue, indigo and violet. When white light hits a white object, all the colours are reflected back. When white light hits a red object, red is reflected back, and the other colours are absorbed.

It's thought that humans can see around 1 million different colours!

In this investigation, ice cubes are placed on black and white paper plates to demonstrate that a black surface absorbs heat faster than a white surface, which reflects most of the light and heat away.

Colour and temperature investigation

You'll need

Two equal sized ice cubes

Black and white paper plates or cardstock.

Timer

Sunny day

Instructions

Find a sunny spot and place one ice cube on a square of black card and one on a square of white card. Both ice cubes must be in direct sunlight or both in the shade.

Time how long each ice cube takes to melt.

The photos show that the ice cube on the black card melted much faster than the one on the white card, which is what we expected to happen. The black card heated up faster than the white and melted the ice cube more quickly.

Extension tasks

Try the activity again using more colours.

Design a t-shirt for a hot day, thinking about the best colours to use. Remember, black absorbs heat, and lighter colours reflect it.

More easy science for kids

See first-hand how light travels in straight lines with a light maze.

Find out how to make a rainbow on a sunny day.

Find out where visible light is on the electromagnetic spectrum.

Science concepts

Light

Electromagnetic spectrum

Vision

The post Does colour affect temperature? appeared first on Science Experiments for Kids.

Have you ever wondered why balls bounce? This activity uses differently shaped balls to investigate how and why balls bounce differently.

I've included FREE instructions for a science investigation to find the bounciest ball with a handy table for recording results.

Balls to use:

• Rugby ball
• Football
• Tennis Ball
• Ping pong Ball
• Basketball
• Squash ball

Look at the differently shaped balls and try bouncing them on the floor. What do you notice?

Things to think about

Which ball do you think will be the hardest to bounce in the direction you want it to bounce?

Are there any similarities between the balls that bounce the highest? What kind of sport are they used for?

Can you bounce each ball into a container? Are some harder than others? Is this related to the type of game they are usually used for?

Why do balls bounce science investigation

This simple science experiment investigates how the shape and size of a ball affects how far and for how long it bounces.

You'll need
Pen and paper
Different types of balls
Tape measure
Chalk

Instructions
Look at the different types of balls and try bouncing them gently on the floor.

Place the balls in order from most bouncy to least bouncy.

Use a long ruler or tape measure and chalk to mark heights of 0.25m, 0.5m, 0.75m, 1m, 1.25m, 1.5m and 1.75m on a wall outdoors.

Drop the balls gently one by one and record the height of the first bounce. Try to use the same force each time and drop each ball from the same height.

Record the number of bounces each ball makes before stopping.

Repeat 3 times for each ball and calculate the average height reached and number of bounces.

More investigation ideas

Try dropping the ball without extra force and then applying force to find out when it bounces higher.

Observe which balls jump straight upwards and which bounce off at an angle.

Remember - when comparing how different balls bounce, consider the conditions you should keep the same, such as the height from which the ball is dropped and the force used to drop it.

Why do balls bounce?

When a ball is dropped, gravity pulls it toward the ground, slowing it down so that each bounce is shorter and shorter until, eventually, the ball stops bouncing.

The force of the ball hitting the hard ground puts an equal force back onto the ball, meaning it bounces back up. This happens because balls are made from an elastic material, allowing them to be squashed or stretched and then return to their original shape. If the ball was made of a softer material, like plasticine, it would be squashed on the ground and wouldn't bounce back up, or if it were made of a hard material, such as glass, it would break when dropped.

Why do balls stop bouncing?

When a ball is held in the air, it has potential energy ( this is the energy stored in the ball because of its height ). When the ball is dropped, gravity pulls it down, and the potential energy is converted into kinetic energy. When the ball hits the ground, some energy is lost in the collision, and so the ball loses energy each time it bounces until there's no energy left.

Remember - energy is always conserved; the total energy is not lost, but changes form.

Extension ideas

Try bouncing your balls on different surfaces to investigate how changing the surface, changes the bounce.

More Sporty Science for Kids

Test your reaction time using just a ruler! This is great fun to do with a friend to find out who has the fastest reaction time. You can also investigate to find out if your reaction time can be improved.

Try one of my 20 easy sports science investigations for kids! These include finding out how much sugar certain drinks contain, how to keep bones strong and healthy and even making a model lung!

Try this fun investigation into skipping rope lengths from Science Buddies.

We've also got lots more exciting science experiments to try. I'd love you to take a look around!

Don't forget to tag me on social media if you try any of our easy science experiments for kids. We loved seeing them in action!

The post Why do balls bounce? appeared first on Science Experiments for Kids.

In this science activity, you can put a balloon into a candle flame without it popping! How is that possible? It's all about heat transfer.

A balloon filled with air will pop when it gets too close to a flame as the heat from the candle warms the balloon's skin and weakens it. The trick to making an unpoppable balloon is to add water to it. The heat from the flame heats the water instead of the balloon, which then doesn't burst.

If you thought putting a skewer through a balloon was impressive, the unpoppable balloon science trick will blow your mind!

You'll need

Two balloons

Water

Safety goggles

Candle

Matches

Plate

This activity requires adult supervision.

Unpoppable Balloon Instructions

Put safety goggles on.

Light the candle and place it safely on a plate. A tea light candle works well.

Blow up the first balloon and slowly lower it over the lit candle. The balloon will pop.

Half blow up the second balloon and add about 200ml of cold water. Blow it up to the same size as the first one.

Lower the balloon over the candle again. The balloon should be able to touch the flame and not pop.

Why does the balloon containing water not pop?

It's all about heat transfer. When the first balloon moved near the candle, it popped because the heat from the candle weakened the balloon skin, which then burst.

The balloon containing water didn't pop, as the water absorbed the heat energy from the candle, not the balloon skin. Thanks to the water, the balloon didn't get hot enough to burn. Water is much better at absorbing heat than air.

The black substance on the bottom of the balloon containing water is carbon from the candle flame.

Make it an investigation.

To make this activity an investigation, think of a variable to test and a question to answer. Some ideas are:

• How much water is needed to stop a balloon popping?
• Does a bigger balloon burst more easily than a small balloon?
• Does the time a balloon can sit in a flame increase if more water is added?

More science experiments using a balloon

Find out how to burst a balloon with an orange.

Learn about burps with burping balloons.

Design and build a balloon powered car.

Make a balloon rocket with Science Bob!

Discover how a hot air balloon works.

The post The Unpoppable Balloon Science Trick appeared first on Science Experiments for Kids.

A solar eclipse is when the Moon passes between the Sun and Earth, blocking the sun's light. People on Earth who are in the path of the moon's shadow will be able to see the eclipse. The Sun is 400 times wider than the moon and 400 times farther away, which is why they appear the same size in the sky.

Solar Eclipse Resources and Activities

Find out how to view an eclipse safely with AAS. Earthsky also has some great tips and advice for protecting your eyes during an eclipse.

Frugal Fun for Boys has a brilliant DIY Pinhole Projector for viewing a solar eclipse.

Learn about the phases of the moon with some creative challenges.

Try some fun maths challenges related to the eclipse.

Make a model of a solar eclipse.

The Royal Astronomical Society has a great solar eclipse worksheet.

Where can you see the April 2024 Eclipse?

The solar eclipse on April 8, 2024, can be seen from a band around 115 miles wide that crosses 15 states from Texas to Maine and parts of Mexico and Canada. This is called the path of totality. The NASA website has a great eclipse explorer interactive map, so you can find out if you live in an area where the eclipse will be visible.

Solar Eclipse Facts

A solar eclipse only occurs during the new moon phase.

During totality, the Moon perfectly covers the sun.

The Moon is 400 times smaller than the Sun.

The Sun is 400 further away from the Earth than the Moon.

When the Moon passes in front of the Sun, it casts a shadow over the Earth.

Eclipses don't occur every month as the Moon's orbit is tilted.

Partial solar eclipses are fairly frequent, total solar eclipses are rare.

During the period of totality, when the Sun is completely covered, the solar atmosphere ( the corona ) is visible.

The first recorded solar eclipse was October 22, 2134 B.C.E.

Read about the history of eclipses.

When is the next solar eclipse?

The next total solar eclipse visible from the USA will be August 23rd 2044.

The next total solar eclipse visible from the UK will be 2090!

Remember ALWAYS to protect your eyes during a solar eclipse.

For more fun space science activities, check out my book This Is Rocket Science.

Affiliate links

The post Solar Eclipse Resources appeared first on Science Experiments for Kids.

This simple science experiment and demonstration is a great way to show children what happens to gases when they are heated.

The air around us is an example of a gas. Particles in a gas can move freely in any direction. Gases don't have a fixed shape but fill the space they have.

When a bottle with a balloon on top is placed in hot water, the air inside warms up. Warm air particles move faster and with more energy than cooler air particles, increasing the volume of the air and inflating the balloon.

Hot and cold air balloon experiment

You'll need

One empty 500ml plastic bottle

A balloon

Two bowls

Hot water and cold water

Instructions

Carefully place the balloon over the bottle opening. Check for holes. The balloon needs to be airtight.

Carefully half-fill one bowl with cold water and one bowl with hot water.

Place the bottle in the hot water bowl and watch as the balloon fills with air.

Transfer the bottle to the cold water bowl and watch as the balloon deflates.

Investigation ideas

Experiment with different water temperatures and record how long it takes for the balloon to inflate at each temperature. For this to be a fair test, you'll need to make sure the air inside the bottle is at room temperature before placing it in each bowl of water.

Investigate to find out how long the balloon takes to deflate after being in different temperature waters for the same amount of time.

Why does the balloon blow up?

Placing the balloon over the top of the bottle traps the air inside. When the bottle is placed in hot water, the air inside heats up. Warm air molecules move faster than cooler air molecules. The warm, faster moving air expands and moves into the balloon, inflating it. The volume of the air in the bottle increases as it heats up.

As the air cools, the air molecules start to move more slowly and closer together. This means they take up less space, the volume decreases, and the balloon deflates.

Fun facts about air

The air we breathe contains about 78% nitrogen, 21% oxygen, and 1% other gases such as carbon dioxide, argon, neon, and methane.

Humidity is the amount of water air can hold before it rains.

Air pressure is the pressure is the pressure of air pushing down on the Earth's surface.

The air around us also carries small particles of dust, pollen and pollutants from car exhausts and other sources.

We need air to breathe!

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This DIY stomp rocket is one of the simplest things I've ever made and works amazingly well! Even our heavy kitchen roll and cardboard rocket flew high up into the air.

All you need to make your own stomp rocket is an empty 2-litre plastic bottle, plastic tubing and paper. It's that simple!

Once the stomp launcher is made, children can experiment with rockets made from different materials to see which fly the furthest.

How to make the easiest stomp rocket ever!

You'll need

An empty 2l plastic bottle

Plastic tubing

Tape

Paper/card

Felt tip pens

Instructions - DIY Stomp Rocket

Attach the plastic tubing to the end of the plastic bottle. My tubing screwed on tightly, but if it's loose, you might need to tape it so no air can escape.

Make a rocket from either a kitchen roll/paper towel tube or a roll of paper.

Seal one end of the rocket with paper or tape.

Decorate the rocket - optional.

Place the rocket on the end of the tubing and squeeze the bottle hard. The rocket will shoot up into the air.

We also experimented with a piece of paper folded over and sealed at the side and top, which worked really well.

If you have any different designs for a homemade stomp rocket, I would love to see them!

How does a stomp rocket work?

When you jump onto the plastic bottle, the air is forced out through the plastic tubing. The force of the air hitting the rocket pushes it into the air.

DIY Stomp Rocket - Extension Ideas

Set up an investigation to determine if making a rocket heavier means it doesn't travel as far.

Change the length of the plastic tubing to investigate how the flight of the rocket changes.

Try pointing the end of the stomp rocket straight up and then forward to find out how the trajectory of the rocket's flight changes.

Buy a stomp rocket launcher and compare it to your homemade version.

More rocket science ideas for kids

A water-powered bottle rocket is the most powerful rocket we've made. This type of rocket shoots upwards very quickly, so remember to stand well back!

My straw rockets are very easy to make and a brilliant, simple rocket STEM challenge.

A squeezy bottle rocket is a fun indoor rocket activity.

Watch a video of a real rocket launch! This one below is amazing as the boosters come back to down Earth and land in a specific place!

Science concepts

Forces

Gravity

Mass

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Hot air balloons work thanks to convection currents. The heat source under the balloon heats the air inside. A convection current inside the balloon keeps the air warm as heated air continually rises, cools and falls to be heated again.

The warm air inside the balloon is less dense than the cooler air on the outside, making the air balloon rise upwards.

Launching a hot air balloon in warm weather is much harder than in cool weather, as the air inside the balloon has to be heated more on a hot day to make it less dense than the external air. If temperatures get too high, the lining of the balloon can be damaged.

The image below shows the convection current inside the balloon heating the air.

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Rockets make a great science project or space-themed STEM Challenge as they are fairly easy to make, can be personalised however you want and reused over and over again. These easy rockets kids can make are also fun craft projects and can be turned into a science investigation!

My personal favourite rocket is our mini bottle rocket. It's quick to set up and doesn't fly up with too much force, but it is still very impressive to watch!

If you love space science, don't forget to check out my book This IS Rocket Science, which contains SEVENTY space-themed science ideas for kids!

Easy Rockets Kids Can Make

This milk jug rocket is sometimes called a rocket mouse. It's low prep, mess free and fun for little people.

A rocket mouse is also a great first science activity for learning about forces!

Air Rocket Launcher

An air rocket launcher is easy to make. It requires only a two-litre plastic bottle, tape, and a small segment of PVC pipe.

The rocket part is made from paper rolled around the pipe, so it's a snug fit.

Simple Stomp Rocket

Stomp rockets are always fun, and this one is very easy to make! Pop the rocket on the end and stomp on the bottle.

Mini Bottle Rocket

My mini bottle rockets are my absolute favourite DIY rockets! You need a 500ml bottle, straws or lolly sticks, a cork and some power for the rocket. This could be Alka Seltzer and water, an effervescent vitamin tablet or even baking soda and vinegar.

Children can experiment to find the best combination of baking soda and vinegar or an effervescent tablet and water to make their rocket fly!

This can be turned into an investigation by adding extra weight to the side of the rocket to see how that impacts how far it flies upwards.

Straw Rockets

Straw Rockets are also mess-free, easy to make and can be themed in lots of different ways.

The paper cutout of a rocket is attached to a shorter, wider straw than the one the experimenter blows down. The wider straw is sealed at the top, so when air from the main straw hits it, the rocket flies!

An alternative to this design is using a plastic bottle rocket launcher to push air through the straw.

Film Canister Rockets - adult supervision needed

These are another very easy rocket to make. You can decorate the film canister or leave it as it is. These are ready to launch immediately and can be reused straight away as long as you can find both pieces of the film canister from the previous launch.

Film canister rockets can be set up as a science investigation by adding extra weight to one rocket. Remember to keep all other conditions the same ( amount of water and effervescent vitamin tablet ).

Water Powered Bottle Rocket - adult supervision needed

A water powered bottle rocket needs a bit more prep and shoots up fast and high so you'll need some adult help and a big empty space!

This type of rocket is perfect for a class demonstration or a great space science competition if children design and build their rockets in teams and then an adult launches each one.

Which rocket will you try first?

More rockets kids can make.

What Do We Do All Day has a brilliant balloon rocket craft.

This toilet paper rocket from Mombrite is really cute, too!

More space science for kids

Find out how you can walk the solar system in your back garden.

Discover how craters form using marbles, flour and hot chocolate powder.

Or try one of my other space experiments for kids!

The post 5 Easy Rockets Kids Can Make appeared first on Science Experiments for Kids.

Ice is great for lots of science experiments and investigations. It's cheap, easy to make and always fun to experiment with.

Today, we are going to try a cool science trick where a wire cuts through an ice cube. Ice usually needs to be warmed up to melt, but you can also make ice melt by adding pressure to it. We do this by adding weights to a thin wire placed over the ice cube.

You'll need:

Thin wire, we used fishing rod wire

Ice cubes

1 or 2 weights

Container to rest the ice cubes on

How to move a wire through ice

Place an ice cube on top of a container. The ice cube should be stable.

Cut the wire to a length that will fit over the ice cube but not reach the surface when the weights are added.

Attach a small weight to each end of the wire.

Place the wire over the ice cube so the weights hang evenly over each side.

How does the wire cut through the ice?

When water freezes, it expands as the water molecules arrange themselves in an ordered arrangement which takes up more space than when the molecules are free.

The wire adds pressure to the ice under it, which melts the ice a little bit. When the wire moves down, the water on the top refreezes. This continues as the wire moves through the ice.

Don't forget to try my other ice experiments for kids!

The post Move a wire through ice - ice cutting experiment appeared first on Science Experiments for Kids.

This collapsing bottle air pressure experiment is also a fun science trick! The bottle collapses without anyone pushing or pulling it.

Adult supervision is needed for this activity, as hot water is used

You'll need

Hot water - ask an adult to help

A plastic bottle with a lid - different size bottles are good to compare

Oven or heatproof glove

Instructions

Remove the lid from the bottle. Carefully pour hot water into the bottle until it's about two-thirds full.

Using a heatproof glove, carefully swirl the water around the bottle.

Empty the hot water out of the bottle and quickly replace the lid.

Watch as the bottle collapses in on itself.

Experiment with different sizes and shapes of bottles.

Why does the bottle collapse?

The hot water gives the air inside the bottle energy, allowing the particles to move around more, increasing the pressure inside the bottle. As soon as the hot water is removed from the bottle, the air particles start to cool and lose energy. This reduces the pressure inside the bottle to less than outside the bottle. Air pressing on the outside makes the bottle collapse.

More air pressure experiments for kids

I have six more air pressure experiments you can try, including making water rise into a jar, making a boiled egg drop into a glass and launching a bottle rocket.

Go Science Girls has a fantastic balloon balance activity to demonstrate that air has weight.

Finally, learn about the Bernoulli Principle with a plastic bottle and rolled-up ball of paper.

The post Collapsing Bottle - Air Pressure Experiment appeared first on Science Experiments for Kids.

This straightforward science activity is an excellent demonstration of air pressure! When the lit candle runs out of oxygen, changes in air pressure lead to the water level in the glass rising upwards.

This activity requires adult supervision.

You'll need

Matches

A pint-sized glass or jar

Egg cup or candle holder

Small tealight candle

Water

Small plate

Food colouring - optional

Instructions

Add a little food colouring to a cup of water and mix thoroughly. Pour the coloured water onto the plate so the base of the plate is completely covered.

Place the egg cup in the middle of the plate and pop the tealight candle on top. Make sure the candle is secure and won't fall off.

Make a note of the water level inside the glass.

Light the candle ( ask an adult to help ) and place the glass or jar over the top.

The candle will go out when it runs out of oxygen, and you should see the water rise up into the glass.

What's happening?

The heat of the candle flame increases the air pressure in the glass, which forces some air out. The candle goes out when all the oxygen in the glass has been used up, and the air cools and contracts. The air pressure outside the glass is now higher than inside, so water is sucked into the class until the air pressure is equalized.

Don't forget to look at my other air pressure experiments too!

The post Rising Water Air Pressure Demonstration appeared first on Science Experiments for Kids.

Electromagnets are electrically powered magnets that can be turned on and off. You can make your own electromagnet with a simple battery-powered circuit and a screwdriver or iron nail.

As electricity flows through the wire coiled around the screwdriver, it creates a magnetic field which magnetizes the metal of the screwdriver.

This activity should be supervised by an adult at all times. The circuit should be disconnected when not in use.

What is an electromagnet?

An electromagnet forms when the current flowing through a wire causes a magnetic field around the wire, which magnetises the metal inside the coil.

The long coil of wire is called a solenoid.

How to increase the strength of an electromagnet.

1. Increase the current going through the wire.
2. Add more turns of wire to the solenoid.
3. Use a soft iron core. Iron is used as it doesn’t stay magnetised when the current is turned off.

Electromagnets have lots of uses as the magnet can be turned on and off as needed and can be made stronger or weaker.

Electromagnets are often found in electric bells and loudspeakers and are useful for sorting rubbish and recycling.

Electromagnets are also used in maglev trains. The trains are suspended above the track by magnets, which reduces the friction between the track and the train allowing it to travel very quickly!

To make an electromagnet, you will need

Paper clips to test

Long wire

Resistor

Insulated tape

Screwdriver - not already magnetic or iron nail

Battery pack and batteries

How to make an electromagnet

Attach one end of the long wire close to the handle of the screwdriver using tape.

Coil the wire along the screwdriver as tightly as you can. Tape the wire in place.

Connect the crocodile clips to the battery pack with a resistor between one of the connections.

We used the resistor to reduce the current flowing around the circuit. Without the resistor, the batteries and wire got very hot quite quickly, so always disconnect the circuit when you've finished testing the electromagnet.

Test the electromagnet by placing it near a paperclip. The paper clip should be attracted to the end of the screwdriver.

Extension Tasks

Add more turns of wire to the screwdriver, this should make the magnetic field stronger.

Make an electromagnet using an iron nail, does this work better?

If you enjoyed this activity, don't forget to check out my other electricity and circuit activities for kids.

The post How to make an electromagnet appeared first on Science Experiments for Kids.

Static electricity is great for science experiments; it's easy to create, is safe and can be used in many different ways. We've used static electricity to bend water, make tissue paper jump up to a balloon and create some crazy hairstyles!

These static electricity snakes use tissue paper like my jumping frogs, but this time the tissue paper is cut into a snake shape. When a ruler charged with static electricity is placed over the snake, it can be pulled upwards.

How to make static electricity snakes

You'll need

Tissue paper

Ruler

Woolly jumper or hair

Felt tip pen

Instructions

Carefully cut a snake spiral out of the tissue paper, this can be any size you want.

Decorate the snake with eyes and other patterns.

Rub the ruler on your hair or a woolly jumper for about 30 seconds.

Hold the ruler over the head or tail of the snake and watch it jump towards the ruler.

You can keep moving the tissue paper with the ruler until the charge wears off.

Why does this work?

When the ruler is rubbed on hair or a jumper, it causes tiny particles to move from the jumper to the ruler.

The extra particles on the ruler cause a build-up of static electricity, which attracts the tissue paper.

If you want a more in-depth explanation, head to my What is static electricity? article.

Extension task

Try rubbing the ruler on other materials to see how easily the ruler gains a static charge. Wool and synthetic fabrics tend to be the best to use for creating static electricity.

The post Static Electricity Snakes appeared first on Science Experiments for Kids.

A magnet is an object that produces an invisible magnetic field. A magnetic field is an area where magnetic materials experience a force.

Objects attracted to a magnet are either a magnet themselves or are made from a magnetic material.

The magnetic force in a magnet flows from the north to the south pole, which creates the magnetic field.

Magnet facts for kids

Magnets have invisible magnetic fields.

Compasses contain a tiny magnet.

Only iron, steel, nickel and cobalt are magnetic.

Magnets can also be made from neodymium and samarium ( rare earth metals )

The north pole of one magnet repels the north pole of another magnet. Like poles repel.

North and South poles are attracted to each other.

Did you know Earth is like a giant bar magnet thanks to its iron core? That's why the Earth has a North and South Pole.

You can make a compass with a magnet.

Uses of magnets

To separate different materials in a recycling plant

Toys

Compass

MRI machines

Clasps in Jewellery

What is an electromagnet?

An electromagnet forms when current through a wire causes a magnetic field around the wire.

The long coil of wire is called a solenoid. The magnetic field of a solenoid is the same as that of a bar magnet.

How can you increase the strength of an electromagnet?

There are three ways to increase the strength of an electromagnet.

1. Increase the current going through the wire
2. Add more turns of wire to the solenoid.
3. Use a soft iron core. Iron is used as it doesn't stay magnetised when the current is turned off.

Uses of electromagnets

Bells

Headphones

Induction hobs

MRI machines

Learn more about magnets with my easy magnet experiments for kids!

The post What is a magnet? appeared first on Science Experiments for Kids.

Physics is key to understanding the world around us. While some aspects may seem tricky to understand, many fundamental physics concepts can be broken down into simple concepts, some of which can be demonstrated using basic equipment at home.

This list of 5 physics experiments you can try at home is a great starting point for understanding physics and, hopefully a source of inspiration for little scientists everywhere!

Physics experiments you can do at home

1. Archimedes and Density

The story behind Archimedes' discovery of density is that he was asked by the King of Sicily to work out whether a goldsmith had replaced some gold from a crown with silver. Archimedes needed to determine if the goldsmith had cheated without damaging the crown.

The crown weighed the same as the gold the King had given the goldsmith, but gold is more dense than silver, so if there were silver in the crown its density would be less than if it were pure gold. Archimedes realised that if he could measure the crown's volume, he could work out its density, but calculating the volume of a crown shape was a tough challenge. According to the story, Archimedes was having a bath one day when he realised the water level rose as he lowered himself into the bathtub. He realised that the volume of water displaced was equal to the volume of his body in the water.

Archimedes placed the crown in water to work out its density and realised the goldsmith had cheated the king!

Density Experiment

One fun way to demonstrate density is to make a density column. Choose a selection of liquids and place them in density order, from the most dense to the least dense. Carefully pour a small amount of each into a tall jar or glass, starting with the most dense. You should end up with a colourful stack of liquids!

2. Split light into the colours of the rainbow

Isaac Newton experimented with prisms and realised that light is made up of different colours ( the colours of the rainbow ). Newton made this discovery in the 1660s. It wasn't until the 1900s that physicists discovered the electromagnetic spectrum, which includes light waves we can't see, such as microwaves, x-ray waves, infrared and gamma rays.

How to split light

Splitting white light into the colours of the rainbow sounds tricky, but all you need is a prism. A prism is a transparent block shaped so light bends ( refracts ) as it passes through. Some colours bend more than others, so the whole spectrum of colours can be seen.

If you don't have a prism, you can also use a garden hose! Stand with your back to the sun, and you'll see a rainbow in the water! This is because drops of water act like a prism.

3. Speed of Falling Objects

Galileo's Falling Objects

Aristotle thought that heavy objects fell faster than lighter objects, a theory later disproved by Galileo.

It is said that Galileo dropped two cannonballs with different weights from the leaning tower of Pisa, which hit the ground at the same time. All objects accelerate at the same rate as they fall.

If you drop a feather and a hammer from the same height, the hammer will hit the ground first, but this is because of air resistance!

If a hammer and feather are dropped somewhere with no air resistance, they hit the ground simultaneously. Commander David Scott proved this was true on the Apollo 15 moonwalk!

Hammer and Feather Experiment on the Moon

Brian Cox also proved Galileo's theory to be correct by doing the same experiment in a vacuum!

While you won't be able to replicate a hammer or heavy ball and feather falling, you can investigate with two objects of the same size but different weights. This means the air resistance is the same for both objects, so the only difference is the weight.

Take two empty water bottles of the same size. Fill one to the top with water and leave the other empty. Drop them from the same height. Both will hit the ground at the same time!

4. Newton's Laws of Motion

Sir Isaac Newton pops up a lot in any physics book as he came up with many of the laws that describe our universe and is undoubtedly one of the most famous scientists of all time. Newton's Laws of Motion describe how things move and the relationship between a moving object and the forces acting on it.

Making and launching a mini rocket is a great way to learn about Newton's Laws of Motion.

The rocket remains motionless unless a force acts on it ( Newton's First Law ).

The acceleration of the rocket is affected by its mass. If you increase the mass of the rocket, its acceleration will be less than if it had less mass ( Newton's Second Law).

The equal and opposite reaction from the gas forcing the cork downwards propels the rocket upwards ( Newton's Third Law ).

4. Pressure

Pressure is the force per unit area.

Imagine standing on a Lego brick. If you stand on a large brick, it will probably hurt. If you stand on a smaller brick with the same force it will hurt more as the pressure is greater!

Snowshoes are usually very wide. This reduces the pressure on the snow, so the shoe sinks less as people walk over the snow.

Pressure and Eggs

If you stand on one egg, it will most likely break. If you stand on lots of eggs with the same force, you increase the area the force is applied over and, therefore, reduce the pressure on each individual egg.

That's five easy physics experiments you can do at home! Can you think of any more?

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The Coriolis Effect refers to how the objects moving on the surface of the Earth appear to follow a curved path due to the rotation of the Earth. It is named after Gaspard Gustave de Coriolis who first described the effect.

The Coriolis Effect influences the movement of wind.

Wind is moving air caused by differences in air pressure. Energy from the sun warms air above land and sea. Warm air is less dense than cold air so it rises creating an area of low pressure. Cooler air moves to where the warm air has risen from creating wind!

Air tries to move from an area of high pressure to an area of low pressure.

Wind mostly blows from one direction on Earth. Warm air rises near the Equator and flows towards the Poles where it cools, sinks and flows back to the Equator. HOWEVER, most winds don't flow directly from north to south as they are also bent by the rotation of the Earth. This bending is caused by the CORIOLIS EFFECT!

Learn more about wind with my wind experiments and activities!

The post What is the Coriolis Effect? appeared first on Science Experiments for Kids.

This mini science investigation shows you how to make a DIY barometer to measure air pressure. Air pressure can be used to predict the weather and is one of many factors meteorologists use to predict the weather.

What does low or high pressure mean for the weather?

Low pressure usually means wet, cloudy, rainy weather, while high pressure indicates dry and cool weather.

Barometers are used to measure atmospheric pressure.

What is atmospheric pressure?

The Earth has a layer of air surrounding it. This air has weight and presses down the Earth. At higher altitudes, the air is thinner, so air pressure is lower.

To make a barometer you will need

Jar or coffee can

Elastic band

Pin or cocktail stick

Tape

Glue

Straw

Paper

How to make a barometer

Blow up the balloon a little bit, the more air in the balloon, the greater the pressure outwards which is what makes the balloon blow up.

Let the air out of the balloon and cut the tie end off.

Stretch the balloon tightly over the jar or can and either tape or use the elastic band to fix it tightly.

Tape or glue the end of the straw to the centre of the balloon and tape the pin or cocktail stick to the end.

Tape some paper behind the barometer and mark where the pin is.

Leave for a few days and note any changes. Record what the weather is like each day and note how it affects the barometer.

How does the DIY barometer work?

Warm air expands and rises, lowering the air pressure on the ground below. Cold air is heavier, it sinks and presses down on the ground forming a high pressure area.

The higher the air pressure the more air presses down on the balloon, pushing it into the jar and making the straw rise.

More weather activities for kids

Did you know you can make a weather station using pine cones?

Find out how movement of hot and cold air causes a sea breeze.

Find out what shape a raindrop really is.

Or, try one of my other weather science experiments for kids.

Science concepts

Air pressure

Atmospheric pressure

The post How to make a Barometer appeared first on Science Experiments for Kids.

Long, sunny summer days are a great time to experiment with shadows. I've put together a fun list of shadow activity ideas with ( hopefully ) something to appeal to kids of all ages.

I use chalk pens for drawing shadows as they are a bit less messy than normal chalk and last a long time.

What is a shadow?

For a shadow to be formed, an object must block light. The object must be opaque or translucent to make a shadow. A transparent object will not make any shadow, as light passes straight through transparent objects.

Transparent Materials

Transparent materials let light pass through them in straight lines so that you can see clearly through them.

Translucent Materials

Translucent materials let some light through but scatter the light in different directions. We can not see clearly through translucent materials.

Opaque Materials

Opaque materials do not let any light pass through them.

Shadow Experiments for Kids

Shadow Frame

Make a shadow frame using cardboard and contact paper. These are great for experimenting with different shapes and types of materials. Try translucent and opaque materials to investigate how the colour of the shadow changes.

Draw Shadows

Use building blocks to make shapes you can draw around. Children can think about how the shadow changes when the object is rotated and observe shadows at different times of the day.

3D shapes are fun to draw around too!

I love how Rhythms of Play painted inside their shadows! Another idea is to draw around a person's shadow and then add organs or a skeleton inside.

Sundial Experiment

Rhythms of Play also has a fantastic human sundial experiment. You can use the same idea to make a smaller version using a LEGO tower on white paper.

Another idea similar to making a sundial is to follow a shadow through the day, watching how the size and shape of a shadow formed by the same object changes!

Shadow Puppet Theatre

Build a shadow puppet theatre like Inner Child Fun. This would be great for linking shadows to literacy work.

Shadow Experiments - Shadow People

Try building people or animals with pipe cleaners. It was quite a challenge to get ours to stand up. Kids can experiment with different sizes and shapes of shadow people.

Shadow Experiments - Shadow Sculptures

The Artful Parent has some brilliant shadow sculptures. It could be quite fun to use the same idea but make models of chemical molecules and draw the shadows too.

Shadow Puppets

Childhood 101 has some brilliant Star Wars shadow puppets.

We love these Gruffalo's Child shadow puppets too.

You could also try some Christmas or other holiday-themed shadow puppets. We made a big Christmas tree shadow puppet and then smaller puppets for the decorations.

More Shadow Experiments

Try experimenting with shadows at different times of the day. You should find that the Sun makes the longest shadows at the beginning and end of the day when the Sun is lowest in the sky and the shortest shadows at midday when it's highest in the sky.

Suitable for Early Years Foundation Stage

Suitable for Key Stage 2 Science

Light

Can you think of any more shadow activities for us?

Science concepts

• Light
• Shadows

The post Shadow Experiments and Activities for Kids appeared first on Science Experiments for Kids.

What is a pendulum?

A pendulum is an object hanging from a fixed point that swings backwards and forwards when pulled back and released. Imagine sitting on a swing in a park. If someone pulled the swing back and let go the swing would move backwards and forwards and eventually stop without another force to keep it moving. The movement slows because of friction acting between the air and the swing.

Energy transfer and a pendulum

As a pendulum swings gravitational potential energy is transferred into kinetic energy and then back to gravitational potential energy.A pendulum is a great way to demonstrate how energy is transferred.

The swinging movement of a pendulum is due to gravity and the back and forth movements are called oscillations.

What is the period of a pendulum?

A period is the time it takes for a pendulum to swing back into the position it started from. The period of a pendulum increases with pendulum length.

This simple pendulum painting activity is a great way to demonstrate how a pendulum moves.

Pendulum Painting

You'll need

3 wooden garden sticks

Small paper cup

Scissors

String

Paint

Pen

Small container for paint

Water

When you pull back and release the cup it swings like a pendulum. Paint falls from the cup as it moves showing the path of movement.

Instructions

Tie the top of the three sticks together to make a tripod shape.

Check the frame is secure.

Carefully use a pen to make a small hole in the bottom of the paper cup. This is to allow the paint to drip through.

Make two more holes in the cup, one on either side at the top. Thread a long piece of string through the holes and tie like the photo below. The cup needs to be hanging from a single point. Attach the other end of the string to the centre point of the tripod.

Check the cup swings like a pendulum.

The paint needs to be quite thin to fall easily from the cup. Mix one tablespoon of paint with 2 tablespoons of water and stir well.

Pour a little paint into the cup and let the pendulum swing.

Extra challenge

Try swinging with more and less force and observe how the pendulum path changes.

Experiment with a longer and shorter string.

Examples of pendulums

A swing

Grandfather clock

Newton's cradle

Foucault's Pendulum

Science Concepts

• Energy
• Gravity
• Motion

The post Easy Painting Pendulum appeared first on Science Experiments for Kids.

Energy is the capacity for doing work and can exist in many different forms. Energy cannot be created or destroyed but can be changed from one form to another. We call this conservation of energy.

Forms of energy

There are lots of different forms of energy.

Kinetic energy

All moving objects have kinetic energy. A ball rolling, a car moving, and a person running all have kinetic energy!

The faster an object moves, the more kinetic energy it has.

Light energy

Objects that give off light have light energy. The sun, candles and light bulbs all have light energy.

Thermal energy

Objects that are warmer than zero degrees have some thermal energy. The hotter an object is, the more thermal energy it has.

Gravitational potential energy

Objects that can fall ( i.e. are above the ground ) have gravitational potential energy. Books on a shelf, a ball held in the air and aeroplanes all have gravitational potential energy.

The further from the ground an object is, the more gravitational potential energy it has.

Chemical energy

Things that can release energy in a chemical reaction have chemical energy. Batteries, petrol and other fuels are good examples of chemical energy stores.

Elastic potential energy

Objects that can stretch, such as elastic bands and springs, have elastic potential energy.

Sound energy

Vibrating objects transfer energy to the air as sound.

Nuclear energy

Energy stored in atomic nuclei is released in a nuclear reaction.

What is an energy store?

Energy stores are different ways of storing energy. Energy can be transferred between or stored in energy stores.

Types of energy transfers

There are four different types of energy transfers. Energy is almost always wasted as it is transferred. If you think about a light bulb, electrical energy powers the bulb to create light energy, but some energy is also lost as heat.

Mechanical energy transfers

If a force acts on an object, energy is transferred by the force to the object. An example of this is pushing down on a catapult.

Electrical energy transfers

Electrical energy transfers involve charges moving around a circuit because of a potential difference.

Heating

Hotter objects transfer energy to cooler objects. An example is a pan of water being heated on a hob.

Radiation

In this type of energy transfer, waves transfer energy. An example of this is light energy from the sun travelling to Earth or sound waves travelling from person to person.

Energy transfer activity ideas

These activity ideas are all straightforward ways to demonstrate energy transfers.

Make a catapult

In a basic catapult model energy from the person pushing down on the catapult arm is transferred to elastic potential energy as the catapult arm is pushed down. When the catapult arm is released, the ball's elastic potential energy is transferred to kinetic energy. These are all mechanical energy transfers.

Play rounders or cricket

In a game of cricket or rounders, kinetic energy from the body of the person hitting the ball is transferred to the bat, and then kinetic energy from the bat is transferred mechanically to the ball. The ball has gravitational potential energy, which is again transferred into kinetic energy. The kinetic energy of the ball increases as it gains momentum until it hits the ground.

Build a Newton's Cradle

A Newton's Cradle is a great way to demonstrate both conservation of energy and momentum.

When the balls are at rest they have zero potential energy and zero kinetic energy as they are stationary.

If one ball is lifted, it gains gravitational potential energy, but the kinetic energy remains at zero. As the ball is released, it loses gravitational potential energy and gains kinetic energy and momentum. When the ball reaches the bottom position, it has its maximum momentum and kinetic energy.

When the ball hits the next ball, it stops and loses momentum and kinetic energy. However, momentum and energy cannot be lost. They are transferred to the next ball, and then the next ball until the last ball, which is pushed outwards at the same speed the first ball dropped, so energy and momentum are conserved!

Make a Solar Oven

A solar oven is a good example of energy transfer by radiation. Energy from the sun is transferred by radiation to the marshmallows, which makes them melt.

Warm up water

This convection activity is a colourful way to demonstrate energy transfer by heating. The warmer water heats the cooler water by convection.

The post What is energy? appeared first on Science Experiments for Kids.

We've made many different mini catapults before, but this was our first attempt at a large version. We had SO much fun with our giant catapult, inspiring many different investigation opportunities.

You can use balls of different sizes and measure how far they travel or how high they go. Another idea is to dip balls in paint and create a piece of catapult art. You can also use the paint to help measure where the balls land!

This is a great activity for learning about forces and different types of energy.

What is a catapult?

A catapult is a device used to launch a projectile ( in this case a tennis ball ) a large distance.

Materials

Five long sticks

Two smaller sticks

String

Catapult Elastic

Different size and shape balls to test

A small plastic container - we used a plastic Starbucks Frappuccino lid!

Catapult Building Instructions

Build a frame using the sticks and string.

Cut three pieces of catapult elastic and attach them evenly around a plastic container.

As shown above, attach the other ends of the elastic to the base and sides of the catapult structure.

Test your catapult!

Catapult Investigation Ideas

Try using different-sized balls to investigate which travel the furthest.

Construct a bigger and smaller catapult to investigate whether the size of the catapult affects how far the balls travel.

Questions to ask

How can I measure the distance the balls travel?

Which conditions should be kept the same?

Does the size of the catapult affect the distance a ball travels?

If a less stretchy elastic is used, do the balls travel as far?

How can the catapult design be improved?

More sports science ideas for kids

Try one of my easy football themed STEM challenges.

If you enjoyed this activity, you might like my other sport themed science investigations.

Contains Affiliate Links

The post How to Make a Giant Catapult appeared first on Science Experiments for Kids.

The question 'How old is the universe?' has intrigued astronomers for centuries. The discovery of leftover light from the big bang was not only supporting evidence for the big bang theory but also allowed scientists to calculate the age of the universe. The big bang is the current accepted theory of how the universe began and the start of time as we know it.

After the big bang the universe expanded very quickly. As it expanded it cooled. Remember energy cannot be created or destroyed, so all the energy in the universe today was around at the time of the big bang!

As the universe expanded the energy became stretched out over a bigger area and so the universe cooled and became less bright.

The first atoms formed about 380,000 years after the big bang when electrons and protons joined together. Photons ( another really small particle ) cooled and stretched to form cosmic microwave background radiation or CMB radiation. It is this radiation that scientists measure to learn about the beginning of the universe.

By estimating how far light from CMB radiation has travelled to reach Earth, the age of the universe can be calculated.

Scientists agree that the Universe is about 13.8 BILLION YEARS OLD.

Learn more about the universe

Learn more about the universe with Chromoscope. Chromoscope lets you explore the Universe in a range of wavelengths!

Help scientists search for new worlds by joining The Backyard Worlds: Planet 9 citizen science project.

Make a simple model of how the universe is expanding.

Science Concepts

• The Big Bang
• Atoms and subatomic particles
• Electromagnetic radiation

The post How old is the Universe? appeared first on Science Experiments for Kids.

The Big Bang is a theory about how the Universe began. Most scientists believe the Big Bang theory which is the current accepted model for the beginning of the Universe.

Georges Lemaître first proposed the big bang theory in 1927. The theory was supported by Edwin Hubble's research into cosmological red shift in 1929.

What is the Universe?

The Universe is basically everything that exists, it is phenomenally large and always expanding.

What is the Big Bang theory?

The Big Bang was a massive expansion ( not an explosion ) from a single point. It was the start of time and the Universe has been expanding ever since.

It's hard to understand but forces, time, matter, energy and every physical thing in the Universe expanded out of that single point.

The Big Bang - a summary

• All the matter in the Universe occupied a very dense, very hot and very small space.
• A sudden expansion occurred and the Universe as we know it started to form.
• Around 13.8 BILLION years later the Universe exists as we know it!

Despite its explosive beginning the Universe as we know it today took a VERY long time to form. Our solar system wasn't created till around 9 BILLION years after the Big Bang! To put this into context the Universe is thought to be around 13.7 billion years old.

Is there any evidence for The Big Bang Theory?

There most definitely is!

Evidence for the Big Bang Theory

Red Shift

Scientists have noticed an increase in the wavelength of light ( shifted towards the red end of the visible light spectrum ) coming from far away galaxies. Measurements of red shift show that far away galaxies in all directions are moving away from us.

Galaxies further away have greater red shift than those closer which shows that far away galaxies are moving away faster.

If galaxies are moving away from us that means they were once closer!

Cosmic Microwave Background Radiation

Cosmic Microwave Background Radiation ( CMBR ) is low frequency electromagnetic radiation that can be detected in all directions throughout the universe. It is though this is the leftover energy of the Big Bang!

Are there any other theories for how the Universe started?

Steady State Theory

The Steady State theory states that the Universe has always existed as it does today and as it expands new matter is created. There's no beginning or end, just a constant state of expanding universe and new matter that keeps the density of the Universe about the same.

What will happen if the Universe keeps expanding?

No one knows...but there are a few theories.

The Big Chill

In this scenario galaxies will become so far apart they run out of gas to make new stars. Existing stars would slowly run out of power and the Universe would become cold and dark.

The Big Crunch

In this theory the Universe expands and then starts to pull back together. Eventually the whole Universe would collapse into one very dense point.

The Big Rip

The Big Rip is a theory where space expands and expands until eventually everything is ripped apart.

We may not know how or if the Universe will end, but we do know that it's not going happen for billions of years!

Science Concepts

• Space
• Matter
• Energy
• The Big Bang

More reading

Read an interesting debate about a Universe with no beginning.

Could there be a multiverse?

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Can you believe it's been over 50 years since humans landed on the moon for the first time? This historic event was not only an incredible feat of science and engineering but also led to many innovations that have improved human life since. If you have children who are fascinated by space travel ( or if you want to inspire them ) this fun collection of space themed science experiments will make a great home space camp!

Don't forget I also have a fun space themed book This Is Rocket Science, which explores the principles behind space flight explaining difficult concepts through simple but exciting, hands-on and easy space themed experiments.

DIY Space Camp for Kids

Docking in Space

Docking in space is quite a task, if you've seen the movie Apollo 13 I bet you were holding your breath when the astronauts had to dock with the lunar module. This fun docking activity is very simplified but a nice, simple demonstration of how tricky docking in space must be. It requires a bit of teamwork so it is a great first space camp activity!

Did you know Apollo 14 struggled to dock the Command Service Module with the Lunar Module?

Our Expanding Universe

Did you know the Universe is expanding? A fun way to demonstrate this is with a balloon!

How does the Earth orbit the Sun?

Discover how the earth orbits the sun and the moon orbits the earth with a super simple orbit activity.

Space Camp - Make a parachute

Discover why parachutes are sometimes used to slow the descent of spacecraft returning to Earth with our fun egg parachute activity. This is a great activity for introducing the concept of air resistance and gravity to kids.

Moon Phase Cupcakes

Learn about the moon with our moon phase cupcakes. Do you know we only see one side of the moon because of how it and the Earth rotates?

Difficulties in space

Try threading pipe cleaners through a colander with bare hands and then wearing thick gloves or washing up gloves. It should feel much harder when wearing gloves.

Imagine being an astronaut and having to do something delicate whilst wearing a space suit!

Make a Rocket!!

A film canister rocket or an easy bottle rocket are both brilliant ways to end a week of space camp! Just remember to stand back as they both fly upwards with a bang.

These are both fantastic for teaching children about Newton's Laws of Motion in a fun hands on way too!

Learn about famous space scientists

Katherine Johnson worked at NASA for over 30 years and played a vital role in putting humans on the moon for the first time. She was also the first African-American woman to attend graduate school at West Virginia University.

Learn about Copernicus's theory of heliocentrism by taking it in turns to play the role of the sun, moon and earth as they orbit each other.

Isaac Newton's infamous Laws of Motion provide the basis for space travel.

Carline Herschel was a pioneering astronomer and the first woman to discover a comet!

Space Camp - Camp out and stargaze

It's not a space camp without some stargazing!

If you can, it's good to camp somewhere away from too much light pollution, but even a back garden stargazing campout is great fun.

Top Tips for Stargazing with Kids

Remember to wrap up warm and use a red torch to help you see in the dark. You can easily make a red torch by attaching a piece of red cellophane over the end of the torch.

Download an app to help identify what you can see, SkyView is a great one to start with.

For more long-term stargazing, start a star diary or journal and record what you can see each night.

The Plough is always a fun group of stars to find, as it looks like a saucepan. It's actually part of Ursa Major, which is a constellation.

Orion's Belt sits in the constellation of Orion ( the Hunter ). The belt is three bright stars in a row, which are usually easy to spot!

Another famous star to locate is the North Star, which sits directly above the North Pole and tends to stay in the same position.

What do you think? Will our DIY space Camp be a hit with your children?

Space Camp Booklet

To make it a bit easier, I've pulled a few activities together into a little space camp booklet, including a moon phase log book and stargazing log pages.

Day 1 - Mini Bottle Rocket

Design, build and launch a mini rocket!

Day 2 - Expanding Universe

Use a balloon to model our expanding universe!

Day 3 - Egg Drop Parachute

Create and test a parachute for an egg.

Day 4 - Phases of the Moon

Learn about the phases of the moon, make an edible moon phase model and observe how the moon changes each day.

Day 5 - Stargazing

Find out how to be a successful stargazer and keep a log of the night sky.

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Hedy Lamarr and George Antheil

Hedy Lamarr (1914-2000 ) and George Antheil (1900 - 1959 ) invented a system which allowed radio waves to jump onto different frequencies. The idea was originally to stop the US Navy's radio signals from being jammed by their enemy in World War 2.

Hedy's invention of radio frequency jumping technology was a vital step in the development of Wi-Fi. Although Hedy Lamarr and George Antheil successfully received a patent for their frequency hopping idea in 1942, it wasn't recognised until many years later when an updated version was used during the Cuban Missile Crisis in 1962.

Hedy Lamarr was not only a scientist but also a famous Hollywood actress in the 1930s and 1940s. She didn't invent Wi-Fi but did work on a concept that ultimately led to Wi-Fi.

Vic Hayes

Vic Hayes is often called the Father of Wi-Fi. He was the head of the committee that introduced the international standard for wireless networking in 1997.

Dr John O'Sullivan

Dr John O'Sullivan led a team of scientists in Australia who worked on groundbreaking technology to reduce the echo of radiowaves. This led to the development of the wireless LAN.

You can see how it's difficult to name a single inventor of Wi-Fi as its development was built on ideas and inventions from multiple people.

What does Wi-Fi stand for?

Some people think Wi-Fi stands for Wireless Fidelity, but it actually doesn't stand for anything!

What is Wi-Fi?

Wi-Fi is a wireless networking technology that allows wireless devices such as laptops and mobile phones to access the internet. It's also known as WLAN which is short for wireless local area network.

Most people use a small wireless router to connect to the internet.

What radio frequencies are used for Wi-Fi?

Currently, radio frequencies of 2.4 gigahertz and 5 gigahertz are used.

If you want to learn more about the history of Wi-Fi the National Museum of Australia has a great overview.

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Hooke's law states that the amount of force applied to an elastic object is proportional to how far it stretches.

However, if the object is overstretched it will not spring back.

Hooke's Law only applies if an elastic object is not overstretched.

Objects are made from lots of molecules with bonds between them, if too much force is applied the bonds break meaning the object will not return to its original shape.

Hooke's Law applies to elastic objects, but they don't stretch forever. When an object will no longer return to its original size we say it has reached its elastic limit.

How to investigate Hooke's Law

One way to investigate Hooke's Law is to add increasing masses to a spring and measure how far the spring stretches ( extends ) until it will no longer return back to its original length.

You should find that the extension of the spring is proportional to the force added.

F = force

k = spring constant

x = length of extension or compression

Deformation is when a force changes the shape of an object either by stretching or compressing it. Different materials respond differently to forces.

Who was Robert Hooke?

Robert Hooke was a brilliant English polymath who discovered the law of elasticity which we now know as Hooke's Law.

Hooke also invested the compound microscope which he used to look at all types of objects revealing a tiny world of micro-organisms that people hadn't seen before. He published a book called Micrographia containing drawings of his findings which included a flea and a head louse. He is also thought to be the first person to use the word 'cell'.

Robert Hooke was born in 1635 and died in 1703. He worked with Robert Boyle and helped form the Royal Society. Hooke is also famous for his clashes with Isaac Newton.

More science for kids

Have a go at one of my many science investigations for learning about forces.

Try this simple stretchy material investigation for learning about elastic limit.

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This simple investigation is great for learning about stretchy materials. The challenge is to find a material that stretches easily and also returns to its original size.

Don't forget to check out my other ideas for learning about materials and their properties too, including sorting objects from Ariel's cave, creating a superhero cape and saving a dinosaur from some bad weather!

You’ll need

Different materials to test

• Elastic bands
• String
• Ribbon
• Balloon
• Elastic

Ruler

Small bag

Clamp

Marbles

Paper

Pencils

Instructions

Make sure the different test materials are all the same length.

Use a clamp to firmly hold the first test material in place.

Measure how long the material is from the bottom of the clamp.

Place 4 marbles in the bag and attach to the bottom of the first test material.

Measure how long the test material is now and calculate how much is has extended.

Repeat 3 times adding more marbles to the bag each time.

Repeat for each test material and record the results.

Which material is the stretchiest?

Remember to use the same amounts of marbles for each test material.

As an example, you could test each material with 4,8 and 12 marbles.

Does the elastic band reach a point where it no longer jumps back up to its original length? If this happens the band has reached its elastic limit.

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This mini wave machine is a great way to demonstrate the concept of a wave! It's easy to make, looks great and can be used over and over again!

What is a wave?

When you imagine a wave do you think of rolling waves in the sea? Radio waves or sound waves flying through the air? Or light travelling from the sun?

Waves are all around us all the time.

Waves transfer energy and information without the transfer of matter.

Waves can be transverse or longitudinal. This mini wave model is a great demonstration of a transverse wave.

Make a Mini Wave Machine

A block of wood around 30cm long

2 screws

Drill or screwdriver

String

Toothpicks

Tape

Jelly tots or other small sweet

Instructions

Carefully drill a screw into the wood at each end. Ask an adult to help.

Tie string as tightly as you can around each screw so you make two parallel lines with the string.

Place a strip of tape underneath the string.

Add toothpicks at regular intervals along the tape and secure with more tape over the top.

Place jelly tots or other small sweets on the ends of the toothpicks.

Push down on one jelly tot and watch as the ripple travels to the end of the model and back.

This wave model shows a transverse wave.

What is a transverse wave?

Transverse waves have vibrations perpendicular to the direction of travel of the wave.

Another way to show this movement is to wiggle a spring or a slinky up and down.

All electromagnetic waves are transverse waves.

What is a longitudinal wave?

In a longitudinal wave the vibrations are parallel to the direction of travel, they squish up and the stretch out again.

Longitudinal waves can also be demonstrated using a spring if you push one end and watch the ripple!

Examples of longitudinal waves are sound waves

Things to note - wave model

The disturbance of the toothpicks travels from one end of the model to the other end and back, but the toothpicks and jelly tots themselves do not move along the string. When waves travel through a medium such as air, the air particles vibrate and transfer energy but stay in the same place like the jelly tots.

Increase the amplitude of the wave by pushing the first toothpick down further.

Increase the speed of the wave by taking the jelly tots off, and slow it down by adding heavier sweets!

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Matter is made up of tiny particles called atoms!

How many states of matter are there?

There are actually 5 states of matter.

The three main states of matter are, solid, liquid and gas. These are the three that occur most commonly on Earth. Water is the only substance that exists in all three states at natural temperatures!

What are the 5 states of matter?

Solid

Molecules tightly packed together and don't move around much.

Particles in a solid have strong bonds between each other.

Solids have a fixed volume and shape.

The molecules in a solid can vibrate but the structure doesn't not change.

Solids cannot be compressed.

Examples of solids are: metals, wood

Liquid

Molecules more spread out and can move around and bump into each other.

Bonds between particles are weak.

Liquids have a fixed volume but can change shape. They take the shape of the container they are in.

Liquids can be slightly compressed.

Examples of liquids: water and oil

Gas

Molecules are far apart can move around freely and quickly.

Bonds between particles are very week.

The shape and volume of a gas are not fixed.

Gases can be compressed.

Examples of gases: oxygen, carbon dioxide, steam ( water vapour )

Plasma ( not the stuff that's in your blood )

Plasma is made when gases are heated to such high temperatures that electrons are ripped away from the atoms to form an ionised gas!

Almost all the visible universe is made of plasma.

We use plasma for fluorescent lights and plasma TVs but it also has lots of exciting medical uses.

Bose-Einstein Condensate

Bose-Einstein Condensate is a state of matter which forms when particles ( bosons ) are cooled to almost absolute zero.

The diagram below shows how solids, liquids and gases change state depending on temperature.

Remember - an atom is a small unit of matter and a molecule is a group of atoms bonded together.

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Voltage is the force that pushes current around a circuit. Imagine a battery being like a pump, pushing the current around the circuit. A more complicated way of defining it is that voltage is the difference in electrical energy between two points on a circuit.

You can buy batteries with different voltages or use multiple batteries to increase the voltage in a circuit. The bigger the voltage the more current flows around a circuit.

How is voltage measured?

Voltage is measured in volts.

The voltage of a standard AA battery is 1.5V.

The voltage of household wiring varies around the world but is 230V in the UK and 120V in the US.

When we made a potato battery we used a voltmeter to check the voltage.

What is current?

Current is the flow of charge ( negative electrons ) around a complete circuit. If the circuit breaks the current stops flowing. Current is measured in Amperes!

You can learn more about electricity and circuits with one of my easy electricity projects.

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How do we see things? We see things because of light!

The simple explanation

Light bounces off objects and enters our eyes allowing us to see them.

It's harder to see at night as there's less light to bounce off objects.

Let's make it a bit more complex

Light enters the eye through the cornea ( the bit on the front of the eye ). The pupil controls the amount of light entering the eye. If you look in the mirror on a sunny day you'll notice your pupil is small, but it becomes bigger when there's less light allowing more to enter the eye.

As the eye is curved it bends the light entering it and so an upside down image is created on the retina which the brain very cleverly turns the right way up.

Muscles around the lens allow it to slightly shape allowing the eye to focus light on the retina.

What are sources of light?

The sun, light bulbs and fire are sources of light.

Facts about light

Light travels in straight lines.

Light can pass through transparent ( see through ) materials but not opaque materials.

Shadows form because light cannot pass through the object casting the shadow.

Light takes about 8 minutes and 20 seconds to travel from the Sun to the Earth.

Light can be natural or human made.

We can see the moon because it reflects light from the sun!

Visible light is made up of lots of all the colours of the rainbow. A prism can be used to split white light into its constituent colours.

Did you know there are different types of light? Gamma rays, microwaves and the rest of the electromagnetic spectrum are all types of light.

Rainbows form because water droplets split light into the colours of the rainbow.

Thomas Edison invented the lightbulb.

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Friction is created when objects are pulled past each other. Imagine pushing a box of books along a carpet and a wooden floor. It would be much easier to push the box along a wooden floor as the smooth surface means there's less friction between the objects.

Let's experiment with friction

We've made friction ramps before, but this version is so easy I wanted to share it as well.

You'll need

A medium size tray

Small toy figure

Bubble wrap

Books ( to raise the tray )

Felt

Timer

Instructions

Divide the tray into three lengthways and choose two different surfaces to test. The third surface will be the smooth inside of the tray.

Place five books under the tray and check the toy figure slides down the ramp without a push. If it doesn't, add a few extra books.

Place the toy at the top of the ramp and time how long it takes to reach the bottom on each surface.

If you want extra reliable results, repeat each slide three times and find the average time for each.

Remove a book and try again.

Keep going until the toy no longer slides down the ramp.

Results

The bubble wrap is the roughest surface in our tray, so this is the slide with the most friction between the toy and the ramp. The bubble wrap slide was the slowest.

The fastest slide was the inside of the tray which is smooth. Therefore little friction is created as the toy slides down the ramp.

The science investigation below is slightly different but on the same theme. Simply print and follow the easy instructions!

Is friction helpful?

Sometimes! Thanks to friction, objects can start and stop moving. Friction also prevents objects from slipping around. We would probably fall over more if it wasn't for friction.

Imagine trying to ride a bike on an ice rink and then on a pavement. Ice is a smooth surface, so there's not much friction, which is why it's slippy. The pavement is not smooth, so there's more friction between the bike tyres and the pavement making it much easier to ride a bike on. Without friction riding a bike on any surface would be like riding on ice!

However, friction also leads to some energy waste, as it's a force that must be overcome. Often heat is produced when energy is transferred between objects which also wastes some energy. Oil is used on bike chains and in the moving bits of a car engine to reduce friction between parts and reduce the amount of heat produced.

Friction always slows an object down, so it's helpful if you want to keep something moving!

Friction Facts

Friction is a force, we can't see it, but we can see its effect.

Friction acts in the opposite direction of the object moving!

There's more friction between two rough objects than between two smooth objects.

Liquids also experience friction; the more friction between liquid layers, the more viscous ( thick ) the liquid is.

Take a look at my full size friction ramp and find lots more ideas for investigations and experiments for learning about friction!

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Radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays and gamma rays are all types of light, but with different energies!

The different types of light have different wavelengths.

What is wavelength?

Wavelength is the length of one wave. The longer the wavelength the less energy the waves have.

Radio waves have a wavelength that is a similar size to a building, while x rays have a wavelength the size of an atom! That's a big difference!

Gamma rays have the shortest wavelength and the most energy. They are also the most ionising.

Where do the different types of light in the electromagnetic spectrum come from?

Gamma rays and x-rays - these can come from natural sources such as radioactive elements but can also be man made.

Ultraviolet radiation - the Sun

Visible light - the Sun, lightbulbs

Infrared radiation - the Sun, people

Microwaves - microwaves occur naturally but can also be man-made like those used in microwave ovens.

Radio waves - radio waves are produced when an alternating current flows in an aerial.

Where is electromagnetic radiation used?

Where are gamma rays used?

Gamma rays kill microbes so can be used for sterilisation of objects and food. They are also used for cancer treatments and for medical imaging.

Where are x-rays used?

X-rays are used to view inside objects and materials. You've probably seen an x-ray scanner at an airport that looks for metal objects and if you've ever broken a bone, you may have had an x-ray. X-rays are transmitted by skin but absorbed by denser materials such as bone.

Where is infrared radiation used?

Infrared radiation is used in heaters and infrared cameras for thermal imaging.

Infrared can be used to transfer information between electronic devices and is used in TV remote controls.

Where is UV light used?

UV light is used in fluorescent lights and sometimes for sterilising water.

What's the difference between frequency and wavelength?

Frequency is the number of waves that pass a point each second. Wavelength is the length of one wave.

The longer the wavelength the lower the frequency.

What is ionising radiation?

Ionising radiation can remove an electron from an atom or molecule. These atoms or molecules are then said to be ionised and are unstable.

Gamma Rays, X rays and some types of UV radiation are ionising.

Ionising radiation can lead to changes in the DNA of a cell.

Electromagnetic Spectrum Facts

We can only see visible light.

Different colours of visible light have different wavelenghts.

Gamma rays and x-rays pass through the body which make them ideal for medical imaging.

Electromagnetic waves are transverse waves. They vibrate at 90 degrees to the direction the wave travels.

There are 7 different types of electromagnetic radiation but they merge together to form a spectrum.

The higher the frequency of the EM wave the more dangerous it is to humans.

Radio waves are not absorbed by the body.

Most of the UV radiation from the Sun is absorbed by the Earth's atmosphere, but some is absorbed by the skin where is can cause damage to cells on the surface.

All types of waves in the electromagnetic spectrum travel at the speed on light.

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The Earth is located in a planetary system we call the solar system located in one of the four spiral arms of the Milky Way galaxy. Our solar system consists of 4 inner planets ( Mercury, Venus, Earth and Mars ) and 4 giant planets (Jupiter, Saturn, Uranus and Neptune ). There are also several dwarf planets ( Pluto, Ceres and Eris are just a few ) around 200 moons, and millions of asteroids and comets.

Light from the Sun takes about 555 days to reach the edge of the Solar System compared to 8.25 minutes to reach the Earth. It's clear we're talking about IMMENSE distances which can be hard to imagine.

Astronomical units can be used to make the distances more manageable.

Working out how far each planet is from the Sun can be tricky as the distance changes depending on where the planet in its orbit. I've used average distances for this activity.

What is an Astronomical Unit?

An astronomical unit ( AU ) is the distance from the Earth to the Sun ( about 93 million miles )

Draw the Solar System

An easy way to draw the Solar System is to scale a drawing to 1AU = 1cm and draw each planet starting from the Sun at 0cm.

Walk the Solar System

To walk the solar system, you'll need to convert the Astronomical Units to something walkable.

If you multiply each distance from the Sun by 100cm, you can easily walk and mark out the Solar System, although you will need a big open space.

For example:

Start with the Sun at 0 cm.

Mercury 40 cm

Venus 70 cm

Earth 100 cm

Mars 150 cm

Neptune 30 metres

Another idea is to use toilet paper and roll out a separate strip for each planet along the ground.

Remember 1 AU is 93 MILLION MILES!!! To put this into context the diameter of the Earth is only 7926 miles!!!

Grab the activity sheet below!

Crazy space facts

Did you know 1.3 MILLION Earths would fit inside the Sun?

1320 Earths would fit inside Jupiter ( if there was no space between them ) which is the biggest planet in the Solar System.

Our solar system is part of a galaxy called the Milky Way!

There is a giant black hole at the centre of the Milky Way that weighs more than a billion Suns!

ELEVEN Earths would fit across the diameter of Jupiter.

Mercury spins so slowly that a year is longer than a day!

Mercury has a very thin atmosphere.

Venus is the hottest planet in the solar system, and its air is so thick that it would crush human visitors in seconds.

Olympus Mons on Mars is three times taller than Mount Everest!

IO ( one of Jupiter's moons ) has over 400 active volcanoes.

Saturn has over 60 moons!

Uranus rolls on its side rather than spinning upright like the other planets.

It would take a plane travelling at normal speed over 570 years to get to Neptune!

Saturn is the second biggest planet, but not very dense. If you could make a bathtub big enough, it would float!

Jupiter has 67 moons ( that we know of ).

If you compare our sun to other stars, it's actually quite small. Hypergiant star VY Canis Majoris is 1400 times wider than the Sun!!!

More space science

Find out more about the wonders of space with one of my easy space themed science experiments!

This video illustrates the size of space brilliantly!

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Shadows are formed when light hits an object it cannot travel through. When you see your shadow on a sunny day, your body has blocked light from the sun. Light travels in a straight line. It cannot bend around your body, so you see a shadow.

Shadows change shape during the day as the sun's position changes in the sky.

In the morning and evening, when the sun is low, shadows are longer than when the sun is high in the sky!

Uses of shadows

Sundials have an arm which forms a shadow. The shadow of the sundial arm changes position as the Earth turns throughout the day. They can be used to tell the time!

Learn about shadows with one of my easy shadow crafts or investigations! You can make shadow puppets, a sundial of your own, a fun shadow frame, draw around shadows and lots more!

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Here at Science Sparks, we love anything space related, especially rockets! This baking soda rocket is one of our favourites, as it's super easy to set up and can be launched over and over again!

I also have a water powered bottle rocket, film canister rocket and squeezy bottle rocket you can try too!

How to make a baking soda rocket

To make a baking soda rocket, you will need

Small 500ml bottle - empty

Cork which fits tightly inside the neck of the bottle

Half a piece of kitchen roll ( paper towel )

One tablespoon baking soda - bicarbonate of soda

Vinegar or lemon juice

3 Straws

Tape

Instructions

Use the tape to attach three straws to the side of the bottle, so it stands up upside down.

Pour about 2 cm of vinegar into the bottle.

Wrap the baking soda in the kitchen roll to make a little parcel.

Choose a launch area outside. It needs to be a hard surface.

When you're ready to launch, drop the baking soda parcel into the bottle, quickly add the cork, put the rocket down and stand back!

Warning - make sure you have a clear, empty space and keep observers well back from the launch site as the rocket shoots up very quickly.

Baking Soda Rocket Top Tips

The cork needs to be tight, so the gas cannot escape.

To slow down the reaction, wrap the baking soda ( bicarbonate of soda ) in half a sheet of kitchen roll before adding it to the bottle. This slows down the reaction and gives you time to put the cork in and stand the rocket up.

Why does a baking soda rocket work?

Baking soda and vinegar react to neutralise each other, which releases carbon dioxide gas.

The carbon dioxide gas builds up inside the plastic bottle. When the pressure of the gas in the bottle is high enough, the cork is forced out of the bottle.

The downward force of the cork being forced out of the bottle creates an upward thrust force which makes the bottle shoot up into the air. This is an example of Newton's Third Law.

For every action there is an equal and opposite reaction.

Warning - Take care when setting this up, and wear eye protection as the bottle can shoot up very quickly!

Download my Baking Soda Rocket instructions here.

Baking Soda Rocket Extension Tasks

Different combinations of vinegar and baking soda

Try experimenting with different amounts of vinegar and baking soda to find the perfect combination. Remember, you don't want the reaction to happen too quickly, but enough gas needs to be produced to force the cork out of the bottle!

Lemon juice as rocket fuel

Try lemon or lime juice instead of vinegar. Investigate whether lemon/lime juice is as effective as vinegar.

More Space Science Experiments for Kids

Discover how craters are formed using marbles, flour and hot chocolate powder.

Or why not set up your very own space camp?

If you're looking for EVEN more space science ideas, you can find SEVENTY exciting space-themed experiments in my book This IS Rocket Science!

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All moving objects have momentum.

Another way to think about momentum is how hard it is to stop a moving object. It's harder to stop an object moving quickly than an object moving slowly.

What is the momentum equation?

All moving objects have momentum. Momentum is a vector quantity which means it has size AND direction.

Momentum (kg m/s ) = mass ( kg ) x velocity (m/s )

Easy way to demonstrate momentum

One very simple way to demonstrate momentum is to roll a small ball or toy car down a ramp, so it collides with another ball or toy car at the bottom.

As the ball or car rolls down the ramp, its momentum increases as it picks up speed.

The object at the bottom is stationary until the first object collides with it. During the collision, momentum is transferred from the rolling object to the stationary object, which then starts to move.

The total momentum remains the same after the collision as momentum is always conserved, but as both balls now have momentum, the object that rolled down the ramp has less momentum than it did before the collision, as some has been transferred to the other ball.

What is the relationship between mass and momentum?

You can use colliding balls to demonstrate this too.

This time roll a smaller ball down the ramp; a smaller ball has a smaller mass and a smaller momentum. This means the stationary ball will move further after a collision with a larger ball than a smaller ball.

Why do objects stop moving if momentum is always conserved?

If momentum is always conserved, why do the balls eventually stop moving? The balls eventually stop because other forces are acting on them, such as air resistance and friction which reduce the speed the objects travel at.

One way to demonstrate the effect of friction is by making and testing a friction ramp.

Toy cars travel more slowly down the ramp lanes that are covered in a rough surface as there is more friction acting on the car, slowing it down.

My book This IS Rocket Science has lots more science activity ideas for learning about forces. I would love you to take a look.

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Static electricity is the thing that sometimes gives you a little shock when you touch a metal door handle after walking on a carpet. It makes your hair stand on end when you put a woolly jumper on and can be used for lots of fun science experiments and demonstrations.

This static electricity demonstration shows you how to bend water with a balloon. It works because water is a polar molecule ( one end is negative and one positive ) Water molecules stick together because the positive end of one water molecule is attracted to the negative end of another.

Static electricity builds up on an object when the object gains electrons ( which are negatively charged ). The negatively charged object ( in this case a comb or balloon ) attracts the positive ends of the water molecules making the stream of water bend.

You'll need

A tap with running water

Balloon or comb

Hair or a woolly jumper

How to bend water with static electricity

Charge the balloon or plastic comb with static electricity by rubbing it on your hair or a woolly jumper.

Turn on the tap, so a thin stream of water runs gently.

Place the balloon or comb near the stream of water, but not touching it.

The water will bend towards the comb or balloon.

Why does the water bend?

Water molecules are polar, they have a negative and a positive end. The negatively charged comb or balloon attracts the positive end of the water molecules making the stream of water bend.

More static electricity experiments

Another way to demonstrate static electricity is by making tissue paper frogs jump up to a balloon.

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Have you ever had an electrostatic shock from a shopping trolley or escalator or noticed your hair standing on end when you rub a balloon on it? The shock is caused by static ( non-moving ) electricity, which is caused by electrons building up with no circuit to flow along.

An object that has gained electrons has a negative charge. An object which has lost electrons has a positive charge. When a charged object is near another charged object, the two will either attract or repel each other.

Objects with a charge try to gain or lose electrons to become neutral again. Sometimes, you can see a tiny flash as the electricity is discharged.

Remember - opposite charges attract, and like charges repel

What is an atom?

All materials are made of atoms.

Atoms contain tiny particles called protons, neutrons and electrons (subatomic particles ). Protons and neutrons are found in the nucleus of an atom. Protons are positively charged. Negatively charged electrons orbit the nucleus. Atoms usually have an overall neutral charge.

Why do balloons become charged with static electricity?

Balloons and other objects, like fluffy jumpers, can steal electrons from other surfaces. The extra electrons give the balloon a negative charge, which attracts other things, such as tissue paper, which jump up to the charged balloon.

Why does a balloon charged with static electricity stick to a wall?

When you rub a balloon on your hair, electrons are transferred to the balloon, giving it a negative charge. When you place the balloon on a wall, it sticks. This is because the negative charge on the balloon repels the negative charges on the wall, creating a positively charged surface to attract the negatively charged balloon. This is called attraction by induction.

Why do you get an electrostatic shock?

You get an electrostatic shock when the charge builds up on you, and you touch something that is earthed or vice versa.

For example, if you scuff your feet along a carpet and then touch another person or a metal object, you'll get a static shock as the electrons jump from you to the other object!

How is static electricity different to electricity?

We usually think of electricity as a current that flows.

Static electricity is a build-up of electrons without a current to flow along.

When is static electricity dangerous?

When static electricity builds up on an object, the potential difference between the object and the earth increases. If the potential difference becomes big enough, electrons can jump from the charged object to the earth, creating a spark.

• Sparks in places with flammable materials can cause an explosion.
• Build up of static charge can interfere with radio equipment.
• Lightning is also caused by static electricity and can cause fires when it reaches the ground.

How can you stop static charge from building up?

Objects can be earthed to prevent too much static charge from building up. This means a conductive material gives the static charge a route to travel to the ground, stopping the static electricity from building up.

Uses of static electricity

In a photocopier

Reducing dust and smoke.

In electrostatic sprayers.

Easy static electricity demonstrations

You can use static electricity to make tissue paper frogs jump up to a balloon. This is a lovely, simple activity that can be turned into an investigation by using different types of paper or by rubbing the balloon for various lengths of time on a surface to charge it.

Frugal Fun for Boys and Girls has a great jumping goop investigation.

Make a static electricity spark that looks like lightning.

Find out how to separate salt and pepper using static electricity.

You can also bend a stream of water with static electricity!

Do you have any static electricity experiments to share with us?

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You may have seen our mini Archimedes screw a few months ago. It was a great STEM challenge and worked really well.

Last weekend we decided to take it up a level and make a supersized Archimedes screw!

Supersized Archimedes Screw

An Archimedes screw consists of a hollow tube with piping twisted around it. We made this one using two half pipes taped together with a long strip of clear PVC tubing wrapped around them.

When the pipe is rotated, water travels up the tubing from the lower tub to the higher tub.

As the pipe rotates, a small amount of water moves into the tubing. On the next rotation, more water moves into the tubing, pushing the first section of water further up the tube. This continues until the water has moved all the way up the tubing.

You'll need

A section of pipe

Clear PVC tubing

Tape to attach the tubing in place - duct tape works best

Two containers to hold water

Something to raise up one container

How to make a supersized Archimedes screw

Construct the Archimedes screw like the image above.

Use tape to attach the tubing to the pipe. The tubing should be twisted around the pipe with an end at each end of the pipe.

Experiment with different diameter tubing and length of pipe to find the most efficient Archimedes screw.

Top Tips

The tubing should not be underwater for the whole rotation. It should come out as the pipe rotates.

If your Archimedes Screw doesn't work, try turning it the other way!

Find out more about Archimedes and the history of his creations in my mini Archimedes screw post.

If you enjoyed this activity, you'll love my other STEM challenges!

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The scale was initially designed to show the effects of the wind on a battleship at sea.

When is a hurricane warning issued?

Hurricane warnings are issued when winds reach 12 on the Beaufort scale, but this would only be a category 1 hurricane.

Hurricanes are measured on the Saffir-Simpson scale based on their wind speed.

The scale helps estimate the possible damage a hurricane may cause.

Saffir-Simpson Scale

Hurricanes start over tropical oceans as tropical cyclones (intense, rotating storms ) when they reach 74 miles per hour; they are categorised as hurricanes or typhoons in the Northwest Pacific.

Hurricane Katrina was a category 5 hurricane at its peak, with storm surges over 6m high! Over 1 million people lost their homes, and more than 1000 died.

New Orleans suffered the worst flooding, but the hurricane caused damage in Louisiana, Mississippi, Florida, Georgia and Alabama.

Don't forget to check out my other fascinating science questions and answers!

I also have a vast collection of weather activities you might like and lots more wind experiments!

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We've made lolly stick chain reactions, Easter egg chain reactions and now we have a GIANT chain reaction.

We actually made this a few years ago, but when I looked for the post today I couldn't find it, so there's no photos just this video.

Simply grab a ball ( any size ) and some other bits and pieces and off you go!

Slides, half pipes, skateboards and buckets all work really well!

It was a brilliant outdoor family activity perfect for a summers day!

If you'd rather a smaller version take a look at our Rube Goldberg machine, which includes a fan and a toy car with a needle attached to pop a balloon.

Don't forget to check out our mini Rube Goldberg Machine too!

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We've done this light refraction experiment many times before, but this time it's Alice in Wonderland themed.

A reversing arrows science investigation is very easy and can be made as simple or creative as you wish.

If you don't want to theme it like I have below, just draw arrows on a small piece of card or paper and place them behind a glass of water.

If you like the Alice in Wonderland theme, I have a similar mirror writing activity too!

You'll need

Paper straws

Card or paper

Plasticine

Tape

Felt tip pens

A tall glass of water

Instructions

Create signs like I have in the image below.

Place a glass of water in front of the signs and watch what happens.

Try moving the glass closer to the sign and further away. You should find that if you move the glass closer to the sign the image is not reversed.

The science of light refraction

The light reaching your eye coming from the arrow is refracted ( bent ) through the glass of water. The glass of water acts like a convex lens (like you might have in a magnifying glass). Convex lenses bend light to a focal point. This is the point at which the light from an object crosses.

The light that was at the tip of the arrow is now on the right side and the light on the right side is now on the left as far as your eye is concerned (assuming you are further away from the glass than the focal point.

Extension Task

Move the arrow image closer to the glass than the focal point. It should now be the way around you expect it to be!

Experiment with different images and text on your signs.

More light refraction experiments

Make a coin disappear with this fun refraction magic trick!

This bending a pencil activity from Raising Lifelong Learners is great too!

Find out how refraction plays a part in rainbows and how to bend light with a prism.

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Forces are all around us and affect everything we do. With that in mind, I've put together a collection of ideas for learning about forces and motion with fun forces and motion experiments for everyone, from preschoolers to grown-ups. There are friction experiments, gravity experiments, air resistance experiments, and lots more! Each activity is easy to set up and works well as a science project for home or school.

If you're looking for a book full of force experiments, This IS Rocket Science might be just what you're looking for! It contains SEVENTY experiments all about the forces involved in space travel!

Let's start with some basics.

Forces and Motion - What is a force?

A force is a push or a pull. Forces can make objects move or stop, speed them up or slow them down. If you push a toy car it moves, if you push it harder it moves faster. Forces can also make objects change direction or shape.

A lighter object needs less force to move than a heavier object. For example you could push an empty box easily, but a filled box would be harder, it would need more force to move.

If you give a toy car a push what happens? It speeds up and then slows down. The reason it slows down is because of two forces, air resistance and friction.

Air resistance is air pushing on a moving object which slows it down.

Friction is the force between two objects when you rub them together. Try rubbing your hands together? Do they get hot? You feel the friction between your hands as heat.

Air resistance and friction take time to slow an object down, if you want an object to stop quickly you need to apply further force, for example a brake on a bike.

Other examples of forces are magnetism, gravity and air pressure.

Over the years we've completed lots of forces experiments on Science Sparks, here are the best ones.

Learn about simple push and pull forces in this easy activity.

Friction Experiments for Kids

What is Friction?

Friction tries to stop objects sliding past each other. Friction allows things to start and stop moving and slows them down.

Imagine sliding two strips of ribbon over each other and then think how hard it would be with two velcro strips. There is more friction between the velcro strips than the ribbon. The amount of friction between two objects depends on what the objects are made from. The rougher the surface the more friction is produced, this is why rockets are streamlined!

Friction Experiments

Find out why you slip and slide more on smooth surfaces than rougher surfaces with this slipping and sliding activity. Do be careful not to fall over though.

A toy zip line is the garden is a great way to learn about friction and fun science project too!

Discover why we salt/grit icy roads in winter.

Investigate which material would make the best ice hockey puck. We want to reduce friction for a good puck as it needs to move quickly and cleanly across the ice.

Learn about reducing friction with this easy Hovercraft

Gravity Experiments for kids

A film canister rocket is a great demonstration of lots of different forces, but it falls back to the ground thanks to gravity.

Water powered bottle rockets are another fantastic example of gravity and lots of other forces too!

Discover a cool science trick to defy gravity using magnets.

Design and build straw rockets and launch at different angles to investigate how the flight trajectory changes.

For younger children, try this fun gravity activity from Inspiration Laboratories.

Making vehicles move - science experiments

We used carbon dioxide released from a baking soda and vinegar reaction to power a bottle boat.

Store up energy in an elastic band to make a cotton reel car move.

Slightly more simple and much more powerful is our balloon powered car.

Red Ted Art made a fun elastic powered tugboat which moves using the energy stored when you wind up an elastic band.

Magnet Experiments for Kids

Make an easy magnet maze with cardboard or even a LEGO maze.

Build some easy magnet powered cars or a magnet powered boat.

How about a magnet sensory bottle?

Air Resistance Experiments for Kids

Explore gravity and air resistance with these simple paper spinners.

Make a parachute, can you save an egg?

Air Pressure Experiments

Watch a boiled egg drop into a bottle with a little science magic.

Make a bottle rocket. Remember you need lots of space for this one as the rocket shoots up quickly and very high!

Watch water rise with a cool air pressure experiment.

Pop the lid off a bottle with these coin poppers.

Make these shooters and explore trajectory and aerodynamics.

How about a film canister rocket? These are great fun, always work, and fly with a pop!

More ideas for learning about forces and motion

Make a simple stomp rocket!

Try this easy inertia experiment where an object drops straight down into a glass!

Learn about kinetic energy with a homemade slingshot or lollystick catapult.

Drop water balloons filled with paint and compare splatter patterns from different heights.

Explore energy and 'bouncy-ness' with some balls and different surfaces.

Try this milk jug rocket craft and experiment from Red Ted Art.

Find out how you can stand on a paper cup without it breaking.

Why do you get dizzy on a roundabout? It's all about the forces.

You could investigate the force needed to break an eggshell.

Finally, do you know why a balloon makes a funny noise when you let it go?

Finally, learn all about Newton's famous Laws of Motion with even more brilliant science experiments for learning about forces.

We'll be adding to this list constantly, so do keep popping back for more great ideas for forces and motion experiments for kids.

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Weight and Mass can be very confusing and people often use them interchangeably without really thinking about which is correct, but very simply:

Mass is a measure of how much matter an object is made up of. Mass remains constant. The mass of an object on the moon ( or anywhere in the universe ) is the same as on Earth.

The weight of an object depends on gravity. There's less gravity on the moon so the same object weighs less on the moon than it does on Earth.

Mass and Weight Facts

Mass cannot be zero. Everything has mass.

Gravity has no effect on the mass of an object.

Mass is often measured in grams, kilograms and milligrams using ordinary scales.

Your weight depends on where you are in the universe. The stronger the gravitational pull the more you weigh!

Weight is a measure of the force of gravity on an object and is measured in Newtons ( N ). A 1 kg mass has a force of 9.8 N on Earth.

Weight (W) = Mass (M) x Gravitational Acceleration (g)

W = mg

How much would you weigh on Jupiter?

Jupiter's gravitational pull is 2.4 that of Earth, so you would weigh 2.4 times more on Jupiter than on Earth.

How much would you weigh on the Moon?

The gravity on the moon is only 16.5% of that on Earth, so you would weigh a fair bit less on the moon. If you weigh 50 kg on Earth you'd only weigh 8.3 kg on the moon!!

If you think about the astronauts on the International Space Station. Their mass doesn't change much in the journey to the space station, but they weigh a lot less when they get there because of the lack of gravity!

How much would you weigh on another planet?

This very cool interplanetary weight calculator on the Exploratorium website works out on your weight on all the planets and some stars too!

Density demonstration

Heavy objects are usually very dense. One very cool way to demonstrate density is by making a density column.

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This fun parachute egg drop experiment is a great demonstration of the forces acting on parachutes. If you drop something, it falls to the ground. This is because it is pulled by the gravity of the Earth. You'll notice that some things drop faster than others. This is because of air resistance. Try dropping a piece of paper and a lego brick. Which drops the fastest?

We are going to try dropping an egg on its own, dropping an egg attached to a parachute and an egg in a basket under a balloon.

Egg Drop Experiment

How to make an egg parachute

What you need to make a parachute

• Bin bag/ plastic sheet/paper or other flat material.
• 4 pieces of string
• sellotape or masking tape
• 3 eggs ( we boiled ours )

Parachute Instructions

• Lay the bin bag out flat and cut out a big square.
• Make a hole in each corner, thread a piece of string through it and tie a knot.
• Tie all 4 pieces of string together and sellotape the egg to the bottom

Make Your Own Air Balloon

Air Balloon Materials

• Cardboard made into a basket shape or a small plastic container
• Balloon blown up
• 4 pieces of String

Air Balloon Instructions

• Sellotape some string to your balloon and attach the basket.
• Place the egg in the basket

Drop an egg on its own, the egg in the basket and the egg in the parachute from somewhere high up. Make sure an adult is around to help with this part.

Gravity and Air Resistance Explained

If you tried dropping paper and a lego brick or similar, the paper should have dropped to the floor more slowly than the brick. This is because the paper has a larger surface area, so has to push against more air as it drops, which means the air resistance is greater, and it drops more slowly.

An egg dropped without anything to slow it down will fall fast and break; the parachute and balloon add air resistance, slowing the fall and stopping the egg from breaking.

We also found that the parachute fell much more slowly than the balloon. This is because the parachute has a larger surface area than the balloon, and so slows the descent of the egg more.

If we dropped a hammer and a feather, we would expect the hammer to fall fastest; however, if we did this on the moon where there is no air resistance, they would hit the ground at the same time!

How do Parachutes Work?

As we explained above, two forces act on an object as it falls. Gravity pulls the object down, and air resistance slows the fall.

Parachutes are used to slow the fall of an object by increasing air resistance which reduces the effect of gravity!

More parachute investigation Ideas

Record the time taken for all three to drop and see how much slower the parachute is.

Try our experiments you can make fly.

Experiment with different sizes of parachutes and see which drops more slowly.

Don't forget to try our collection of easy ideas for learning about forces too.

In This IS Rocket Science we made parachutes with coffee filters which was great fun and you can experiment with different sizes and shapes.

If you liked this science experiment you'll LOVE my book This IS Rocket Science, which has 70 space themed science experiments for kids!

This post was originally published in 2011 and updated July 2019

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We've done a couple of simple activities based around forces recently, so when a sheet of bubble wrap arrived in a parcel, I knew just how to use it.

We laid the bubble wrap sheet flat on the floor and talked about what we wanted to investigate and what we expected to happen.

Bubble Wrap Forces Investigation Ideas

• Try to walk over the bubble wrap gently enough so the bubbles don't pop.
• Test to see if the result is the same for a heavier and lighter person.
• Do the bubbles pop if you jump?
• If you jump harder, do the bubbles pop more loudly?
• What happens if you drop a light and a heavy ball onto the bubble wrap?
• Try to think of a way to measure the loudness of the popping. Try asking a friend to stand in a different room and see if they can hear the popping under different conditions.
• Design a table to record your results.

Can you think of any more bubble wrap force investigation ideas for us?

More Forces Activities

For more ideas for learning about forces, including air resistance, friction, and gravity, check out my other forces experiments.

Ideal activity for Early Years and Key Stage 1 Forces.

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Building a mini hovercraft is a great way to learn about friction.

Hovercrafts are really interesting as they move on top of a layer of air. The layer of air reduces friction allowing the hovercraft to move quickly over land and sea. We've been learning about friction recently, which is a complex topic to grasp, but a mini hovercraft made with a balloon and CD is a helpful demonstration.

You'll need

• A CD you don't need.
• Hot/cold glue gun - ask an adult to help
• A pop-up lid from a drinks bottle
• Balloon

How to make a mini hovercraft

• Take the lid off the drinks bottle. Discard the plastic cover cap and ensure the pushdown mechanism is down.

• Glue around the bottom rim of the pop-up lid and attach it to the centre of the CD over the hole in the middle. Make sure there are no holes for air to escape through.

•  Push the pop-up lid down.

• Blow up a balloon and place it over the pop-up lid. The balloon should stay inflated. Place the hovercraft on a smooth surface.

• Lift up the lid and watch the hovercraft move!

The hovercraft should shoot across the surface as the air is forced out the bottom.

Extension task

Try the hovercraft on a rough surface, such as a carpet. What happens?

What is Friction?

Friction is created when two objects try to slide past each other. Friction can slow you down if you're trying to move. Generally, the rougher the surface, the more friction there is. Real hovercrafts use a powerful fan to pump air underneath themselves. There's less friction between the bottom of the hovercraft and air than there would be between the hovercraft and water. This allows hovercrafts to move very quickly.

Our balloon hovercraft reduces friction between the CD and the surface by blowing air from the balloon between them.

More friction experiments

Race toy cars down ramps covered with different materials. The cars should move faster down the ramps that have smooth surfaces.

Build and test mini garden zip lines for toys. A zip line made with a rough string should be slower than one made with a smooth string if all other conditions are the same.

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Pushes and pulls are examples of forces.

When we push or pull something, it moves.

Can you push a toy car softly? What happens? Does it move further if you push harder?

Can you think of things you push and things you pull? Are there things you can push and pull?

We drew a simple table with our ideas and then put them into a Venn diagram. The area in the middle where the circles overlap are things we push and pull.

Can you think of any more?

Examples of Push and Pull Forces

Push Forces

Push a scooter

Push a supermarket trolley

Push a swing

Push a bell

Pull Forces

A dog pulling on a lead.

Pull down a zip.

Pull a cracker

Push and Pull Forces

Hockey - push or pull the ball

Push or pull open a door.

If you're starting a push and pull forces topic, you might like my push and pull puppets!

Don't forget to take a look at my full collection of science activities for learning about forces.

Science concepts

Forces

Pushs and pulls

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It's also static electricity that sometimes gives you a shock when you touch something metal. The conductive metal discharges any static electricity that has built up on your skin creating a small electrostatic shock.

To make your hair stand on end all you need to do is blow up a balloon and rub it on your jumper or hair.

Then place the balloon above your hair or some tissue paper and watch the hair or tissue paper become attracted to the balloon.

Investigate

Try recording the time hair stands up for if you rub it across your head, once, 5 times and 10 times.

Do you think there will be a difference?

What is static electricity?

All objects are made of atoms. Inside atoms are protons, electrons and neutrons. Protons have a positive charge, electrons have a negative and neutrons have a neutral charge.

Opposite charges attract each other and like charges repel.

Mostly charges in an object are equal and balanced, static electricity occurs when the charges become imbalanced.

When you rub a balloon on a jumper, you add electrons to the surface of the balloon. Your hair is now more positively charged than the balloon, so when the balloon comes close, the hair is attracted to the balloon and so sticks up on end.

The same explanation works when you stick a static electricity-charged balloon to a wall. Opposite charges attract, so the negatively charged balloon is attracted to the more positive wall.

You could try lots of different items to find out which sticks to the balloon.

More static electricity experiments for kids

Frugal Fun for Boys and Girls shows how to bend water using static electricity.

Try our jumping tissue paper frogs experiment.

Static Electricity Facts

Static electricity is called static electricity because the charge stays in a certain area for a period of time rather than flowing elsewhere.

Lightning is an example of static electricity. Lightning occurs when static electricity builds up in clouds which causes a huge spark to form between the cloud and the ground!

Printers use static electricity to attract the ink to paper.

Electrical components can be very sensitive to static electricity, which is why they are packaged in anti-static bags.

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