Completely Inelastic Collision

hateAleen

After a completely inelastic collision, two objects of the same mass and same initial speed are found to move away together at 1/3 their initial speed. Find the angle between the initial velocities of the objects.

I think that this question is dealing with collisions in two dimensions. My textbook does not give any equations for completely inealstic collisions in two dimensions. Any help?

mgb_phys

It just means they stick together, so you have a final particle of 2*mass

hateAleen

I went through and ended up getting an answer of 45 degrees. But that ended up being wrong.