Purpose: To demonstrate different properties of materials.

Show the difference between the balls by dropping the bounce and no-bounce balls. The "Sad" ball will not bounce as it is made from energy absorbing material, while the "Happy" ball will bounce since it is made from a more elastic material.

These polymer balls may look the same but they behave differently, making them the ideal choice for demonstrating the coefficient of restitution. The happy ball stores very little energy in collisions and bounces well. The sad ball stores a lot of energy and doesn't bounce.

Place the "Sad" ball in the ramp at a predetermined height and let it roll into the metal block to show that it will not knock it over. Repeat the demo with the "Happy" ball to show that it will knock over the block because it has transferred twice the momentum to the block to allow it to bounce backwards.

Be sure to find a ramp elevation that allows the "Happy" ball to just barely knock over the block so that the "Sad" ball doesn't have enough momentum to knock it over.

Can also be used effectively in M74

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