Question

After a completely inelastic collision, two objects of the same mass and same initial speed move away together at half their initial speed. Find the angle between the initial velocities of the objects.

Answer 1

we can see

m(v cos x + v cos y) = 2m(v/2) ...(1)

and

v sin x = v sin y
=>x= y ...(2)

we may now find the angle in between which is x+y..

Answer 2

i havent considered the case where the collide and move together at an angle z from the horizontal as that'd give us 3 variables with 2 eqns..
and for that, you'd have needed the value of co-efficient of restitution..