physics help?

Question

A 1.8 kg ball is attached to a ceiling by a string. The distance from the ceiling to the center of the ball is 1.14 m, and the height of the room is 3.00 m.

(a) What is the gravitational potential energy associated with the ball relative to the ceiling?
J
(b) What is the gravitational potential energy associated with the ball relative to the floor?
J
(c) What is the gravitational potential energy associated with the ball relative to a point at the same elevation as the ball?
J

Answer 1

In general gravitational potential energy is a energy stored that potential y can do work

Pe=mgh

a) Negative gravitational potential energy.
That means we need to add energy to lift the ball to the level of the ceiling

Pe= mg(-h)
h= 1.14m
b)Positive gravitational potential energy
Pe=mgh here
h= (3.0 - 1.14)m
c) Zero gravitational potential energy

Since h=0 Pe=0