Question

Why is there no work done in circular motion?

Answer 1

Circular motion:

1. When an object moves along a circular path, the motion exhibited by it is circular motion.
2. The force working on the object in uniform circular motion is known as centripetal force.
3. In a circular motion, the force applied on the object and the displacement of the object are perpendicular to each other at every point.

Work done:

1. The work done on an object is equal to the dot product of the force exerted on it and its displacement.
2. Since the angle between the force and displacement is $90°$, the dot product will be $0$ $\left(\cos 90°=0\right)$.
3. Consequently, the work done is $0$.

Hence, there is no work done in circular motion.