Mechanics/Dynamics/Motion

Bouncing Ball

This exhibit demonstrates the exponential nature of the frequency of bouncing. The visitor pushes down a plunger and picks up a steel ball bearing on a magnet. Upon release, the plunger rises and the ball drops on a steel plate. The sound of the bouncing ball is amplified and heard on a set of speakers. Since the ball bounces to a height which is a certain portion of its last bounce, the frequency of bounce goes up exponentially. A remarkable aspect of this exhibit is that the frequency of bounce can be as high as several hundred hertz, providing the ball and plate are clean.