Upon spotting an insect on a wing overhanging water, an archer fish squirts water drops at the insect to knock it into the water. Although the fish sees the insect along a straight line path at angle ? and distance d, a drop must be launched at a different angle θ0 if its parabolic path is to intersect the insect. If ? = 360o and d = 0.900m, what launch angle θ0 is required for the drop to be at the top of the parabolic path when it reaches the insect?
