Suppose an olympic diver who weighs 55.0 kg executes a straight dive from a 10 m platform. at the apex of the dive, the diver is 10.8 m above the surface of the water.

what is the potential energy of the diver at the apex of the dive, relative to the surface of the water?

assuming that all the potential energy of the diver is converted into kinetic energy at the surface of the water, at what speed in m/s will the diver enter the water?

does the diver do work on entering the water? (yes/no)
explain.