A ball of mass 1.7 kg hangs at the end of a string 1.2 m in length from the ceiling of a room. The height of the room is 4.0 m.
a) What is the gravitational potential energy of the ball relative to the ceiling?
b) What is the gravitational potential energy of the ball relative to the floor?
c) What is the gravitational potential energy (in J) of the ball relative to a point at the same elevation as the ball?