Question

A body is acted upon by a force. State two conditions under which the work done could be zero.

Answer 1

Work done is zero:

We know, $Workdone\left(W\right)=Force\left(F\right)\times Displacement\left(s\right)\times Cos\varnothing ,where\varnothing istheanglebetweenthedirectionofforceanddisplacement.$

So, for the following two conditions, work done by the force on the body is equal to zero.

1. Displacement is zero: If a body is acted upon by a force but the net displacement is zero, then the work done will also be zero.
2. The angle between the direction of force and displacement is $90°$: Whenever the applied force on the body is perpendicular to the direction of the displacement of the body, then the work done by the force on the body is zero.