1. A solid ball A of mass 10kg travelling to the right at 2m/s collides with a solid ball B of mass 5kg travelling to the left at 5m/s. The collision is elastic. Find the velocities of the balls after the collision 2. Momentum before collision = Momentum after collision 3. (10kg x x2m/s) - (5kg x 5m/s) = 10v + 5v -5 = 15v v = -5/15 = -0.333m/s Could somebody check this please?