A 0.060 kg tennis ball, moving with a speed of 7.60 m/s has a head-on collision with a 0.080 kg ball initially moving in the same direction at a speed of 3.20 m/s. Assume a perfectly elastic collision and take the initial direction of the balls as positive.
a) What is the velocity of the tennis ball after the collision?
b) What is the velocity of the 0.080 kg ball after the collision?