An archer sees two monkeys 30 feet up a tree, 40 feet from the ground. His arrows fly are known with a starting velocity of v, and follow in flight a path shaped like a parabola, affected only by gravity - that is, their speed is sufficient that air friction does not play a significant role during the short flight.
The first monkey just sits there on the branch.
The second monkey is hanging from a branch. At the very instant when the arrow is released it lets go of the branch and starts falling down, with intent to land in the soft undergrowth under the tree, and then make a quick getaway.
How will the archer hit the first monkey? How about the second monkey?