Could you please explain to me these problems, I don't understand them.

Do 100 J of work in 50 s and your power output is?

A bow is drawn so that it has 40 J of potential energy. When fired, the arrow will ideally have a kinetic energy of ?

A diver who weighs 500 N steps off a diving board that is 10 m above the water. The diver hits the water with kinetic energy of?