Question

A stone of mass m is tied to a string of length $\ell$ at one end and by holding second end it is whirled into a horizontal circle, then work done will be:-

• A. 0
• B. $\left(\frac{m{v}^2}{\ell }\right)2\pi \ell$
• C. $\left(mg\right)\cdot 2\pi \ell$
• D. $\left(\frac{m{v}^2}{\ell }\right)\ell$

Answer 1

The correct option is A 0

Work done will be 0 as force is always perpendicular to the velocity vector.

Hence,

option $A$ is correct answer.