# Homework Help: Momentum Problem on a glider

1. Nov 3, 2009

### paulsberardi

1. The problem statement, all variables and given/known data
Gliders C and D, of masses 2kg and 4kg, respectively, collide on a frictionless track. Glider C initially moves to the right with a speed of .6 m/s relative to the track, while glider D is at rest. After the collision, glider C moves to the left with a speed of .2 m/s. System S consists of gliders C and D.

2. Relevant equations
What is the magnitudes and directions of the momentum vectors for glider C, glider D, and system S before and after the collision?

Is the momentum of system S before the collision the same as it is after the collision? Explain.

3. The attempt at a solution
I was able to find the momentum of glider C before and after the collision using p=mv. I also knew glider D would not have a momentum vector before the collision because it is at rest.

I could not find the momentum of glider D after the collision or the momentum vectors of system S.

2. Nov 4, 2009

### Kurdt

Staff Emeritus
You know momwntum is a conserved quantity. Therefore the momentum before should equal the momentum afterwards.