Question

After a completely inelastic collision, two objects of the same mass and same initial speed are found to move away together at 1/2 their initial speed. Find the angle between the initial velocities of the objects.

Answer 1

If they had the same speed, the vertical speed would cancel and the horizontal speeds would sum, since they slowed down to half of their initial speed, half of the speed of each particle would be in the vertical, and half in the horizontal, then the angle between one particle and the horizontal would be pi/4, and the angle between the two particles would b pi/2