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)

zero

Answer 2

Key Idea: Work done (W) = Force(F) x $(W)=Force(F)\times displacement(d)$ 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 $W=F\times 0=0$