Science Rocks -For Kids- Potential and Kinetic Energy

Have you ever blown up a balloon and then let it go, without tying it shut? The air rapidly escapes from the balloon, making it zip all over the room! This is because when you blow up a balloon, you increase the air pressure inside the balloon. This air pressure stretches out the rubber balloon material, just like stretching a rubber band. Both the air pressure and the stretched rubber store potential energy, or energy that is "waiting" to do something.

When you let the balloon go, the rubber contracts, and air is rapidly squeezed out the opening of the balloon. The potential energy inside the balloon is converted to kinetic energy, or energy of motion, of the fast-moving air through the opening.

Because the air is pushed out rapidly backwards, there is a reaction force that pushes the balloon forward. This principle comes from Newton's third law of motion, which states "for every action, there is an equal and opposite reaction."

To build the cotton ball launcher you will need a used pencil, 2 T.P. tubes, 2 thin and very stretchy rubber bands, duct tape, a cotton ball, a single hole puncher and scissors. You may need an adult to help punching holes because it goes through several layers of cardboard. Here is the link to see how to build it!
https://www.youtube.com/watch?v=ZWJfIdZOpP4&t=133s

See ideas on how to build a balloon powered car by going to:
https://www.sciencebuddies.org/science-fair-projects/project-ideas/phys_p099/physics/balloon-powered-car-challenge#background
This site will show pictures of many balloon powered cars:
https://duckduckgo.com/?t=ffab&q=balloon+powered+car&atb=v202-1&iax=images&ia=images
Decide how you want yours to work and look, draw a little sketch of how you want it to look, make it your own with either one or two balloons and have fun!
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