Find their velocities after the collision

[Student91]

A ball of mass 0.198 kg has a velocity of 1.47 i m/s; a ball of mass 0.309 kg has a velocity of -0.401 i m/s.They meet in a head-on elastic collision.

a) Find their velocities after the collision

b) Find the velocity of their center of mass before and after collision

 

[RougeSun]

Since it's an ellastic collision, momentum is conserved. a) can be found with conservation of momentum.