Two 0.40kg soccer balls collide elastically in a head-on collision. The first ball starts at rest, and the second ball has a velocity of 3.5 m/s. After the collision the second ball is at rest.
a. What is the final velocity of the first ball?
b. What is the kinetic energy of the first ball before the collision?
c. What is the kinetic energy of the second ball after the collision?