Here's some answers to some other questions that we've answered that may help (taken from another question on tennis balls that we answered recently). Why do basketballs bounce?
- This is actually talking about basketballs, not tennis balls, but the idea is exactly the same. Bouncing Ball
- This one talks about what the surface youíre bouncing the ball on has to do with how the ball bounces. Hot and Cold Basketballs
- This explains how making a plastic ball hotter or colder will change the way it bounces. The Physics of Baseball and Tennis
- This answer has some links to pages on what science has to do with sports like tennis. Why do tennis balls lose their bounce?
- This explains why tennis balls don't bounce as well when they've been out of their container for a long time.
As for your last question (how can you show how they bounce), the easiest way would probably be to use a bigger ball like a kickball - this will be a lot easier to see. If you let a bit of the air out (but not so much it wonít bounce), you can pretty easily see the way that the plastic moves when the ball bounces. If you use a bunch of different balls that have different amounts of air in them, then you can show why itís so important for bouncing balls to be filled up with air all the way. (You can find a really good explanation on why balls bounce under the "why do basketballs bounce?" question above.) If youíre looking for some more exciting activities, you should definitely check out the links from the "Physics of Baseball and Tennis" answer. Good luck with your project!
(published on 10/22/2007)