- Drop each ball from the same height, and notice how high each bounces back up.
- Now, place the smaller ball on top of the larger one, holding them together. Ask the class to make predictions about will happen when you drop the two as a unit.
- Let go of both the balls at exactly the same time and observe what happens.
Conclusion:
If you dropped the balls at the same time, the tennis ball should bounce off the basketball and fly high into the air. The two balls hit each other just after they hit the ground, a lot of the kinetic energy in the larger basketball is transferred through to the smaller tennis ball, sending it high into the air.
While you held the balls in the air before dropping them they had another type of energy called 'potential energy', the balls gained this through the effort it took you to lift the balls up, it is interesting to note that energy is never lost, only transferred into other kinds of energy.
