Two colliding particles, finding ratio of M/m

[irhum31]

Homework Statement

A particle of mass m and initial velocity v0 collides elastically with a particle of unknown mass M coming from the opposite direction as shown in the left-hand sketch on the next page. After the collision, m has velocity v0/2 at right angles to the incident direction, and M moves off in the direction shown in the sketch. Find the ratio M/m.

Homework Equations

None given, although I'd assume the elastic condition collision equations.

The Attempt at a Solution

I don't even know where to begin.

 

[PeroK]

Welcome to Physics forums.

Have you ever heard of the conservation laws?

 

[irhum31]

Welcome to Physics forums.

Have you ever heard of the conservation laws?

I'm sorry if this question is trivial. It's just I cannot seem to wrap my head around how I can use momentum conservation with kinetic energy conservation to find this ratio, especially when I have no idea what the other velocity is.

 

[PeroK]

So you do know where to begin! I can't see any diagram. Where is M moving after the collision?

If you don't know a quantity, then use a variable. Eventually, you should be able to cancel it out of your equations.

What can you say about conservation of momentum in this collision?

 

[irhum31]

So you do know where to begin! I can't see any diagram. Where is M moving after the collision?

If you don't know a quantity, then use a variable. Eventually, you should be able to cancel it out of your equations.

What can you say about conservation of momentum in this collision?

Aah, sorry. Here's the diagram. It's the one to the left under 6.9. (https://goo.gl/Pc87AW)

Momentum is conserved. Don't think there's more to be said than that, is there?

 

[PeroK]

Aah, sorry. Here's the diagram. It's the one to the left under 6.9. (https://goo.gl/Pc87AW)

Momentum is conserved. Don't think there's more to be said than that, is there?

Hint: Momentum is a vector quantity.

I'm going offline now. I'm sure someone else will pick I up.