# Perfectly Inelastic Collisions

nothing123
Is there a proof showing how perfectly inelastic collisions result in the maximum kinetic energy loss?

Thanks.

## Answers and Replies

Science Advisor
Homework Helper
Is there a proof showing how perfectly inelastic collisions result in the maximum kinetic energy loss?

Thanks.

Hi nothing123!

Well, "perfectly inelastic collision" means that the two final velocities are the same.

So we may as well chose that velocity as our frame of reference.

So the question for you to answer is: If two bodies are stationary, can any transfer of momentum between them (conserving momentum) decrease the energy?

nothing123
Hi tiny-tim,

I'm not sure if I'm following exactly but are you suggesting that if there can be no more transfer of momentum between the objects in the system, it's at its lowest possible kinetic energy? What does the frame of reference have to do with it?

Thanks.

Science Advisor
Homework Helper
Hi nothing123!

We can use any frame of reference.

But it makes sense to choose whatever frame makes the calculation easier.

In this case, it seems to make sense to choose the frame of the final velocity.

But it will work in any frame!

Have a go!

nothing123
Sorry, I'm not quite following...is there supposed to be a calculation that's made?