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

Question

Do 100 J of work in 50 s and your power output is?
- I got 2, but not sure of the units.

A bow is drawn so that it has 40 J of potential energy. When fired, the arrow will ideally have a kinetic energy of ?
I don't understand this queston

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?
I don't understand this question

Answer 1

a Joule/second is defined as a watt.

The second is conservation of energy. The arrow should have the same KE as the bow had PE.

The third is exactly the same, The diver had mgh of PE, he should have that KE at the bottom.