A 0.22 kg billiard ball moving to the right at 2.2 m/s has a head-on elastic collision with another ball of equal mass moving to the left at 0.85 m/s. The first ball moves to the left at 0.85 m/s after the collision. a- Find the velocity of the second ball after the collision,
b- Verify your answer by calculating the total kinetic energy before and after the collision.