What is the change in divers potential energy ?

Question

Hi, I'm struggling with the question B. 

 

 

A diver with a mass of 57.8kg , climbs up a diving board ladder and then walks to the edge of the board. He then steps off the board and falls vertically from rest of water 3.00m below.

A) Determine the divers potential energy at the edge of the diving board, relative to the water.

B) what is the change in the divers potential energy from the diving board to the water.

C) where did his energy go ?

Answer 1

A. Energy = Force* distance.  The force here is gravity = mass*g where g is the acceleration due to gravity = 9.8 m/s².  The diver's mass = 57.8 kg.  The distance is the diver's height above the water = 3 m:

 

Potential Energy = mgh = (57.8)(9.8)(3) = _____

 

B. When the diver hits the water, his height above the water = 0 m.  Plug h=0 into the potential energy equation above.  The change in potential energy is the potential energy at h=3 minus the potential energy at h=0.

 

C.  The potential energy is converted into the kinetic energy of motion.