Question

The work done by the centripetal force $F$ when the body completes one rotation around the circle of radius $R$ is:

• A. $2\pi RF$
• B. $2RF$
• C. $RF$
• D. zero

Answer 1

Answer: (D)

Work done $(W)=$ Force $(F)\times (W)$
$=$ Force $(F)\times$ displacement $(d)$
displacement For a body rotating in circular motion, centripetal force is directed towards the centre of the circle when body completes one rotation, its displacement is zero, hence
Work done = force $\times$ displacement
$W=F\times 0=0$