Work is said to be done when a force applied to an object moves that object. Work done is generally referred to in relation to the force applied while energy is used in reference to other factors such as heat. Power is defined as work done per unit time.
- Work done by the force of gravity on an object depends only on vertical displacement.
- Vertical displacement is given by the difference in the initial and final positions/heights of the object, which is zero.
Work done by gravity is given by the expression,
W= m × g × h
h = Vertical displacement = 0
W = m × g × 0
W = 0 J
Therefore, the work done by gravity on the given object is zero joule.