# Homework Help: Momentum of two objects

1. Oct 16, 2006

### map7s

Object 1 has a mass m1 and a velocity 1 = (2.78 m/s) in the x direction. Object 2 has a mass m2 and a velocity 2 = (3.21 m/s) in the y direction. The total momentum of these two objects has a magnitude of 16.8 kgm/s and points in a direction 66.5° above the positive x-axis. Find m1 and m2.

I tried doing p=mv for each one but it didn't work. I think that it has something to do with the resulting angle, but I don't know how to incorporate that into the equation.

2. Oct 16, 2006

### jamesrc

Write a little more about what you did. You should be trying to break up the total momentum into x and y components (using trigonometry). Then you can equate the momentum of object 1 with the component of the total momentum in the x-direction and the momentum of object 2 with the component of the total momentum in the y-direction.

3. Oct 16, 2006

All you have to do is solve the vector equation: $$\vec{p} = \vec{p}_{1} + \vec{p}_{2}$$, where p is the total momentum, and p1 and p2 are the momentum of masses 1 and 2, respectively.