Question

Ball 2 with a mass of 30kg, is moving to the left at 10 m/s. with what velocity should ball 1, with a mass of 10 kg, move to the right and collide with 2, so that ball 1 rebounds with a velocity of 30 m/s, and ball 2 with velocity of 10 m/s, after the collision. assume the collision to be perfectly elastic.

Answer 1

So for an elastic collision, the total momentum will be conserved. That means, \[m _{1}u _{1}+m _{2}u _{2}=m _{1}v _{1}+m _{2}v _{2}\] where u is initial velocity and v is final velocity.