Question

A ball of mass 2 kg moving with velocity 3ms-1 collides with the another ball of mass 1 kg at rest and after collision the velocity of first ball becomes 2 ms-1. What is the velocity of second ball?

Answer 1

According to law of conservation of momentum,

m1u1+m2u2=m1v1+m2v2

Therefore, 2(3)+1(0)=2(2)+1v

6+0=4+v

6-4=v

v=2 m/s