Question

A body of mass $0.1kg$ is moving along a circle of radius $2m$ with a speed $4m/s$. The work done by centripetal force during half revolution is:

• A. $1.6J$
• B. $3.2J$
• C. $4.8J$
• D. $0$

Answer 1

The correct option is D $0$

$\overrightarrow{F}\perp \overrightarrow{ds}$

Since centripetal force $F$ is towards the center and displacement $ds$ is tangential.
$W=\overrightarrow{F}.\overrightarrow{ds}=0$