A ball is thrown straight up from the ground with speed v 0 . At the same instant, a second ball is dropped from rest from a height H , directly above the point where the first ball was thrown upward. There is no air resistance.
Part A Find the time at which the two balls collide.
Part B Find the value of H in terms of v 0 and g so that at the instant when the balls collide, the first ball is at the highest point of its motion.