What You Will Need:
This demonstration requires only 2 balls. You'll need a small superball and a large superball. A basketball will actually work just fine for the larger ball, and it will make balancing the smaller ball much easier.
What To Do:
First drop each ball serparately from the a distance of about 2 feet. Note how high each ball bounces. Now place the small ball on top of the larger ball and drop them together from about 2 feet. Watch the height of the smaller ball.