Question 304: Work, Energy and Power & Circular Motion

Question

A body of mass $m$ is performing a UCM in a circle of radius $r$ with speed $v$. The work done by the centripetal force in moving it through $\left(\frac{2}{3}\right) \mathrm{rd}$ of the circular path is

Accepted Answer

When a body perform uniform circular motion, then centripetal force acts always in perpendicular direction to its velocity, hence work done by centripetal force is always zero.
Hence, work done by centripetal force is zero, when it through $\left(\frac{2}{3}\right)$ rd of the circular path.

Answer

zero

Answer

$m v^2 \pi r$

Answer

$\frac{2 \pi m v^2 r}{3}$

Answer

$\frac{2 m v^2 \pi}{3}$

Work, Energy and Power & Circular Motion

A body of mass m is performing a UCM in a circle of radius r with speed v. The work done by the centripetal force in moving it through \left(\frac{2}{3}\right) \mathrm{rd} of the circular path is

Choose the correct answer: