# A ball with a mass of # 5 kg# is rolling at #18 m/s# and elastically collides with a resting ball with a mass of #3 kg#. What are the post-collision velocities of the balls?

##### 1 Answer

May 9, 2018

Given

Mass of 1st ball

Mass of 2nd ball

Initial velocity of 1st ball

Initial velocity of 2nd ball

Let post collision velocity of 1st ball be

Again the collision being elastic one the relative velocity of one ball with respect to the other is reversed by the collision and we get

By [1] and [2] we get