A tennis ball of mass 60.0 g is held just above a basketball of mass 602 g. With their centers vertically aligned, both are released from rest at the same moment, to fall through a distance of 1.31 m. Find the magnitude of the downward velocity with which the basketball reaches the ground. Assume an elastic collision with the ground instantaneously reverses the velocity of the basketball while the tennis ball is still moving down. Next, the two balls meet in an elastic collision. To what height does the tennis ball rebound?