PURPOSE: To illustrate coefficient of restitution.

DESCRIPTION: Drop the two balls simultaneously from the same height. One bounces back to almost the original height, while the other stops dead on impact. Which one is happy and which one is unhappy?

The happy ball is made from neoprene rubber; the unhappy ball is made from norbornene, a polymer synthesized from ethylene cyclopentadiene.

SUGGESTIONS:

REFERENCES: (PIRA unknown.)

EQUIPMENT: Happy and unhappy balls.

SETUP TIME: None.