What is Needed
What to Do
This is a very easy experiment, with very dramatic results.
Take two balls, one large and one small, and place the small one on top of the large one, as shown:
Now, drop them together. What happens to the top ball?
What is Happening?
When you drop the two balls together, they will separate just a little bit. The bottom one will hit the ground first, and will rebound. As it is on the way up, it hits the top ball, which is still on its way down. So you have a head-on collision, between balls of very different masses. When this happens, a lot of the energy of the first ball gets transferred to the second ball, and - watch out! The top ball, the small one, will end up bouncing very high indeed!
Other Things to Try
What happens if you put the small ball on the bottom?