# Kinetic Energy and Collision Question

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1. Jun 17, 2016

### bebop1

Is there a threshold of maximum kinetic energy lost when kinetic energy is transferred between two objects through collision?

I just cannot find any information on this, any help would be VERY much appreciated.

2. Jun 17, 2016

### Simon Bridge

Welcome to PF;
How much kinetic energy did the system start with?
That is the maximum that can be lost.

3. Jun 17, 2016

### haruspex

Momentum must be conserved. Their common mass centre therefore continues at the same velocity. Maximum KE loss occurs when they coalesce.
If it is a glancing blow, and the masses are not sticky, then their velocities parallel to the plane of contact will not change. Maximum KE loss when will be when their velocity components along the line of contact become the same.
If they are irregular shapes and the blow is glancing, it gets complicated since some of the energy may turn into rotational energy, so it depends whether you count that as conserved or lost.

4. Jun 17, 2016

### Simon Bridge

There is also the case when a blob of wet clay collides with a fixed wall and sticks...

5. Jun 17, 2016

### haruspex

Are you saying I did not cover that?