Make a balloon stick to the ceiling and make your hair stick up on its ends as you learn about electrical charges.
Have you ever gone down a slide at the playground, and felt your hair sticking up? The slide and your hair rub against each other and create static electricity, which can stick to any surface, unlike other types of electricity that only flow through wires. When you rub the balloon and wool object together, it gives the balloon an electric charge, meaning it is full of static electricity. This charge makes the balloon move towards the wall and stick there even after you move your hand. It also pulls the hair on your arm towards the balloon, even though your arm is not touching it. When the balloon does touch your arm, it loses its electric charge. The static electricity is transferred to your arm and then to the floor, where it spreads out until it has disappeared. Now if you move the balloon up to your hair, it won't stand up, since there is no longer any static electricity in the balloon. Rubbing the balloon again with the wool will create more static electricity and you can do it all over again.
Bend a stream of water using a comb to see how static electricity can pull or push things!
Did you see the stream of water bend towards the comb? The water was pulled towards the comb through static electricity. Rubbing the comb and sweater together created static electricity, which gave the comb an electrical charge. The electrical charge is what drew the water towards the comb. Water is neutral, meaning it cannot have an electrical charge, but it can be pushed away (repelled by) or pulled towards (attracted to) something with an electric force, like the comb that was full of static electricity.
Use a trash bag to make a hot air balloon that gets its power from the sun! You will need to do this experiment on a warm, sunny day without wind.
You should have eventually seen the trash bag slowly start to float up in the air. The sun not only gives light, it also gives heat. The color black absorbs a lot of heat, so the air inside of the black trash bag was warmer than the air outside it. As air heats up, it expands (spreads out), becoming lighter. Since warm air is lighter, it always rises above cool air. The black trash bag started to rise up as the air inside it got warmer. If you used a hairdryer to heat the air inside the bag, the same thing happened, you just used electrical power to heat the air instead of solar (sun) power! The fact that hot air rises is part of the reason why the lower level (or the basement) of a house feels cooler than the upstairs levels.