# Homework Help: Collisions on 2Dimensions.

1. Sep 26, 2007

### Donnie_b

A 5.00 kg Ball A moving at 12.0 m/s collides with a stationary 4.00 kg Ball B. After
the collision, Ball A moves off at an angle of 38.0º right of its original direction. Ball B 52.0º left of Ball A's original direction. After the collision, what is the momentum
of Ball A?

P1 + P2 = P1' + P2'
60 + 0 = P1' + P2'

After this I have no idea where to go. We would need a velocity however there isnt one given.

I'm assuming a vector diagram would be useful, but Im not too sure what that would look like.

2. Sep 26, 2007

### hage567

You must break up the momentum into the x and y components, and sum up in each direction. Draw a diagram to keep track of everything.

3. Sep 27, 2007

### Donnie_b

I dont have the hypotenuse to be able to do that. The only thing I could think of would be x =(60-y) and y=(60-x)

4. Sep 27, 2007

### Donnie_b

Ok so I also asked this question on Yahoo answers, and some person gave me this:

Now I have never seen anything alike this taught to me. Does this have any truth to it?

I was also given this which seems more.... legit

5. Sep 27, 2007

### l46kok

You don't need the hypotenuse to break into components. You have the angle given after the impact, use trigonometry.

[EDIT]

The first response is completely off. The second one seems right to me as well.