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EXPERIMENTING!
This book is packed with exciting experiments that go bang, make a big splat, or are so incredible you wont believe your eyes! But theres nothing magical in these pagesits all real-life amazing SCIENCE.
WHAT YOULL NEED
You can do most of these experiments with everyday items youll find around the house, or can buy easily and cheaply at a supermarket or hardware shop.
Some useful things to have handy are
* Paper and card
* Pens and pencils
* String
* Glue
* Tape
* Straws (plastic ones are best)
* Plates, bowls, jugs, and plastic food containers
* Scissors
* Paper cups
* Balloons
STAY SAFE!
Experiments are fun, but some of them can be dangerous if theyre not done carefully so dont forget these safety tips:
* You will need an adult to help with experiments that involve cooking and heating, matches and candles, and sharp cutting tools. Wherever an experiment has something like this in it, youll see this sign to remind you:
ASK AN ADULT!
* Follow all the instructions carefully to make sure you use all the equipment and materials in a safe way.
* Stand back from anything thats moving fast, or that involves eruptions or explosions. And dont throw, shoot, or whirl things around unless youre completely sure theres no one nearby.
And remember
Always do experiments somewhere thats easy to clean up, like a kitchen or bathroomNOT on the fancy carpet! And make sure you do clean up after yourself. Some of these experiments are messy!
So, are you ready to see some science? Step this way
NOISY EXPERIMENTS
These experiments make loud bangs, weird noises, or cool music, to help you find out what sound really is, and how it works.
What is sound?
Basically, we hear sound when things move and vibrate, or shake quickly to and fro. These movements make the air vibrate, too. The vibrations spread out through the air and reach our ears.
Sound waves
When you drop an object into liquid it makes the water move, and ripples spread out in a circle until they touch the edge. Sound is the same, but instead of spreading out in a flat layer, the sound waves go in all directions.
Moving & shaking
For example, if someone hits a cymbal, the metal vibrates, and that makes invisible ripples, or sound waves, spread out in the air all around it. You hear the sound when the sound waves reach your ears.
Make a noise!
There are lots of ways to make a sound by getting something to vibrate. Try this simple experiment with a balloon:
Blow up a balloon, but dont tie it closed.
Hold the side s of the opening of the balloon, and pull them away from each other.
Slowly let the air out of the balloon. Try stretching the opening tightly and less t ightly as the air escapes to see if you can change the sound.
HOW DOES IT WORK?
As the air pushes through the narrow gap in the opening, it makes the rubbery balloon skin vibrate. This makes a loud squeaking sound.
Watch it
Sound vibrations are often so small or so fast that they can be hard to see clearly. But in this case, you should be able to see the neck of the balloon vibrating in a blur.
GLITTER DISCO
This experiment will let you see the vibrations that sounds makeand get some glitter to dance!
WHAT YOULL NEED:
* A large radio with a speaker on the front, or a hi-fi speaker
* Glitter flakes (not the powdery kindlarger flakes work better)
* A large plastic plate or round tray
* Clingfilm
1. Tear off a large piece of clingfilm and stretch it over the plate so that its as flat and smooth as possible. Tuck the clingfilm under the plate to hold it in place.
2. Get your radio or speaker, and lie it down so that the speaker part is facing upward. You may have to ask someone to hold it steady.
3. Put your clingfilm-covered plate right over the middle of the speaker. If you can see two speaker openings, use the bigger one if there is one.
4. Shake a small amount of glitter onto the middle of the clingfilmabout a teaspoonful. (Be careful not to spill glitter into the speaker.)
5. Play some musicsomething with a clear beat, like rock, disco, or dance musicand turn it up loud (or as loud as youre allowed!).
HOW DOES IT WORK?
When the speaker makes sound, the sound makes vibrations in the air. They pass through the plate into the clingfilm, making it vibrate up and down. Louder sounds make bigger vibrations! This makes the glitter jump in the air and move in time to the music.
Want to try making something else danceor dont have any glitter? Lots of other things work well. Try small sequins, flaky sea salt, or small seeds, like caraway or sesame seeds.
STRAW TROMBONE
If you have a real trombone and know how to play it, youll definitely be able to make a racket. But if not, heres the next best thinga working trombone made out of household items!
WHAT YOULL NEED:
* Two straws, one slightly wider than the other
* A piece of thin card at least 15 x 15cm (6 x 6 inches)
* A pencil
* Scissors
* Clear tape
From the side, your straw should look like this.
1. Take the narrower straw, and flatten one end of it between your fingers. Then use the scissors to carefully snip off the sides to form a point.
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