Question

A tangential force of $F=1.5N$ acts on a particle of mass $m=2kg$ revolving in a circular path of radius $r=3m$. What is the work done by the torque for a complete revolution of the particle?

• A. $9\pi J$
• B. $11\pi J$
• C. $10\pi J$
• D. $12\pi J$

Answer 1

Answer: (A)

$9\pi J$

We Know,

$\tau =r\times F$

$\tau =1.5\times 3=4.5kgm/s$

$W={\int }_0^{2\pi }\tau .d\theta =4.5({\theta }_f-{\theta }_i)=4.5\times 2\pi =9\pi$

Hence Option $\text{A}$ is the correct answer.