# Energy Sharing in Elastic Collisions

1. Oct 5, 2011

### fire526438

A stationary object with mass mb is struck head-on by an object with mass ma that is moving initially at speed v0.
If the collision is elastic, what percentage of the original energy does each object have after the collision?

I don't know how to find percentage.

2. Oct 5, 2011

### grzz

Is the collision assumed to be perfectly elastic? i.e. is the total kinetic energy assumed to be conserved?

3. Oct 5, 2011

### fire526438

kinetic energy conserved

4. Oct 5, 2011

### grzz

There are two principles you can use. Do you know which principles?

5. Oct 5, 2011

### fire526438

kinetic energy & momentum
but how to calculate

6. Oct 5, 2011

### grzz

Correct.
First I would simplify the notation.
Why not call the stationary mass M and the other mass m.
Let m have intial velocity u and let final velocities of m be v and that of M be w.
Now apply those two principles.

7. Oct 5, 2011

### grzz

conservation of KE: (1/2)mu$^{2}$ = ...
conservation of linear momentum: mu =...