Mechanics: Happy-Unhappy Balls

PIRA Class: 1R40.30

Purpose:
To demonstrate how different materials impact the ability for mechanical energy to transform into thermal energy.

Description:
Both balls appear identical yet when dropped one rebounds almost to its drop height and one does not bounce at all.

Optional: After showing the demonstration mix the balls then invite a student to inspect each ball and try to predict which is the ball that will not bounce. The ball that does not bounce is slightly squishier, but still not easy to identify.

Explanation from the packaging

Equipment:
Happy-Unhappy balls

Location:
Shelf 132