Basketball Bounce

Materials: basketball, hard floor or pavement to bounce ball on

To demonstrate gravitational potential energy hold a basketball over your head and release it on to the pavement. Gravity pulls the ball towards the Earth creating kinetic energy as it drops until it hits the pavement converting it back to potential. This conversion from potential to kinetic is repeated as the ball bounces up and down the pavement.

When you drop the ball, note how high it bounces back. Why doesn't it bounce back to the same height at which you let it go? If you let the ball keep bouncing, notice that with it bounces back a little lower each time.

If the ball were to bounce back to the same height at which it was dropped, that would mean all the gravitational energy was converted to kinetic energy. It isn't all movement, though is it? Listen (that's a hint), what other forms of energy can you detect or identify? Think back, too, to the rubber band experiment--can you think of another energy form?