# Elastic collision

1. Nov 16, 2008

### rugbygirl2

1. The problem statement, all variables and given/known data

I have a 4kg mass (m1) moving at 3m/s towards a 8kg mass (m2) at rest on a 2m long frictionless table that is of unknown height. I solved for the velocities after the collsion m1= 2m/s and m2= 1m/, suppose the two masses were placed so that they left the edges of the table in opposite directions at the same time, ie the collision happened so that m2 was placed 0.66667m from the edge. What is the distance that each travels from the base of the table (delta x).

2. Relevant equations

m1= 4kg, and a initial vx of 2 m/s
m2= 8kg, and a initial vx of 1 m/s

3. The attempt at a solution
I do not know the height or time of flight so any way I substitute equations I get 2 unknowns. Any help or ideas would be appreciated!

2. Nov 17, 2008

### tiny-tim

Welcome to PF!

Hi rugbygirl2! Welcome to PF!

You should have two equations, which should be enough for two unknowns.

Show us what you've tried, and where you're stuck, and then we'll know how to help.