# Background Physic

1. Apr 24, 2006

### rachael

What is the background physics of "bouncing a ball?
Momentum and impulse are the background physics but is there any thing else?

2. Apr 24, 2006

### Hootenanny

Staff Emeritus
You may also wish to consider energy.

~H

3. May 21, 2006

### abercrombiems02

More specifically, with energy and collisions there is a dimensionless quantity called the coefficient of restitution. This number is a ratio of KE after the collision to that of the KE before the collision. Thus if the initial first bounce had a KE of 10J at the ground and the coefficient of restitiution was 0.6, then on the ball's way back up, it would be leaving the ground with a KE of 6J (the other 4J are dissipated mostly into heat, vibrations, and material deformation)