A tennis ball of mass mt is held just above a basketball of mass mb and radius Rb. With their centers vertically aligned, both are released from rest at the same moment, so that the bottom of the basketball falls freely through a height h and strikes the floor. Assume an elastic collision with the ground instantaneously reverses the velocity of the basketball while the tennis ball is still moving down because the balls have separated a bit while falling. The two balls meet in an elastic collision. To what height does the tennis ball rebound?