Question

A boat has a cannon on board that faces aft. The boat is capable of traveling at
19 m/s on still water. The boat is traveling North on a river that has a current flowing south at a rate of 10 m/s. Following 20m directly behind the boat is a raft that is traveling at 13 m/s relative to the water. On the raft is a clown with a hoop. The cannon fires the cannonball at 38.5 with velocity 20 m/s. At what velocity must the clown throw the hoop in order for the cannonball to travel through it? Assume the clown throws the hoop straight up.