Question

In case of circular motion of a body, if tangential force also acts on the body in addition to centripetal force, then work done:

• A. by both the forces is positive
  
• B. by tangential force is zero by work done by centripetal force is not zero.
  
• C. by both the forces is zero
  
• D. by centripetal force is zero but work done by tangential force is not zero
  

Answer 1

The correct option is D by centripetal force is zero but work done by tangential force is not zero


As we know centripetal force is along radius vector so centripetal force and displacement is always perpendicular to each other.

Hence, work done by centripetal force is always zero.

But for tangential force angle between displacement and force is $0^{\circ }$.

So, work done is not zero.