A ball is thrown upward with speed V. At the instant the ball is thrown, second ball is dropped from rest at a height H above the thrown ball, but not directly above it. Ignore air resistance. How much time elapses before the balls pass each other? Find a value of H such that the ball thrown upward is at its highest point when the dropped ball passes. For the first question, do I need to come up with an equation for both balls and set them equal to each other to find the time when they pass each other? It seems as if I would have two unknowns when I do this. And for the second question do I need to set the velocity equal to 0 to find when the ball reaches its highest point?