Question

A force $\left(m{v}^2/r\right)$ is acting on a body of mass m moving with a speed v in a Circle of radius r. what is the work done by the force in moving the body over half the circumference of the circle?

• A. $\frac{m{v}^2}{r}\times \pi r$
• B. Zero
• C. $\frac{m{v}^2}{r^2}$
• D. $\frac{\pi r^2}{m{v}^2}$

Answer 1

The correct option is B Zero

Since$,$ the body is in circular motion$,$ the centripetal force $\left(\frac{m{v}^2}{r}\right)$ is directed towards the centre and at any point it is perpendicular to the displacement

hence, the work done is moving the body over half the circumference of the circle is zero

Hence,

option $\left(B\right)$ is correct answer.