What you'll need: * Stiff plastic drinking straws * A raw potato Instructions: 1. Hold a plastic drinking straw by it sides (without covering the hole at the top) and try quicklystabbing the potato, what happens? 2. Repeat the experiment with a new straw but this time place your thumb over the top, covering the hole. What's happening?Placing your thumb over the hole at the top of the straw improves your ability to pierce the potato skin and push the straw deep into the potato. The first time you tried the experiment you may have only pierced the potato a small amount, sowhy are you more successful on the second attempt?Covering the top of the straw with your thumb traps the air inside, forcing it to compress as you stab the straw through the potato skin. This makes the straw strong enough to pierce the potato, unlike the first attempt where the air is pushed out of the straw. |
Use a Balloon to Amplify SoundSmall sounds can still make a big noise when you use agood sound conductor. Experiment with a balloon, compressed air and your own ears to find out how it works and the science behind it. | | |
What you'll need: * Balloon Instructions: 1. Blow up the balloon. 2. Hold the balloon close to your ear while you tap lightly on the other side. What's happening?Despite you only tapping lightly on the balloon your ears can hear the noiseloudly. When you blew up the balloon you forced the air molecules inside the balloon closer to each other. Because the air molecules inside the balloon are closer together, they become a better conductor of sound waves than the ordinary air around you. |
What is Your Lung Volume?Do you think you're fit and healthy? Let's test your lung volume to find out. Just how much air can your lungs can hold?With the help of a few simple household objects, some scientific know how and a dash of curiosity you can make this experiment look easy. | | |
What you'll need: * Clean plastic tubing * A large plastic bottle * Water * Kitchen sink or large water basin Instructions: 1. Make sure the plastic tubing is clean 2. Put about 10cm of water into your kitchen sink. 3. Fill theplastic bottle right to the top with water. 4. Put your hand over the top of the bottle to stop water escaping when you turn it upside down. 5. Turn the bottle upside down. Place the top of the bottle under the water in the sink before removing your hand. 6. Push one end of the plastic tube into the bottle. 7. Take a big breath in. 8. Breathe out as much air as you can through the tube.9. Measure the volume of air your lungs had in them. 10. Make sure you clean up the area to finish. What's happening?As you breathe out through the tube, the air from your lungs takes the place of the water in the bottle. If you made sure you took a big breath in and breathed out fully then the resulting volume of water you pushed out is equivalent to how much air your lungs can hold. Having abig air capacity in your lungs means you can distribute oxygen around your body at a faster rate. The air capacity of lungs (or VO2 max) increases naturally as children grow up but can also be increased with regular exercise. |
Warm Air Needs More RoomAs its temperature rises, air starts to act a little differently. Find out what happens to a balloon when the air inside it heats up with this funscience experiment for kids. | | |
What you'll need: * Empty bottle * Balloon * Pot of hot water (not boiling) Instructions: 1. Stretch the balloon over the mouth of the empty bottle. 2. Put the bottle in the pot of hot water, let it stand for a few minutes and watch what happens. What's happening?As the air inside the balloon heats up it starts to expand. The molecules...