Question

A body moving in a circular path has the zero displacement but there is an acceleration explain why?

Answer 1

Even if it is undergoing uniform circular motion, the acceleration is not constant. It is because the direction of acceleration is changing.

Acceleration is a vector quantity, and thus measuring its change involves both magnitude and direction.

The acceleration undergoing uniform circular motion is given by

a=v^2/r

Yet, the direction is always pointing towards the centre, and thus the direction of acceleration is always changing. So the acceleration does not remain constant.

This is particularly wrong when we don’t consider a uniform circular motion, i.e. with tangential acceleration, as both components of acceleration is changing direction, and thus the overall acceleration.