Question

A particle of mass $7kg$ is executing circular motion with time period of $11sec$. Find out centripetal force if radius of circle is $10m$.

• A. $\frac{30}{7}N$
• B. $\frac{40}{7}N$
• C. $30N$
• D. $\frac{160}{7}N$

Answer 1

Answer: (D)

As we know, $\omega 2\pi f$
$\omega =\frac{2\pi }{T}\left[\because f=\frac{1}{T}\right]$
And, $v=r\omega$
Then, $v=\frac{2\pi r}{T}$
$v=\frac{2\pi \left(10\right)}{11}=\frac{2\times 22\times 10}{7\times 11}=\frac{40}{7}$
Centripetal force,
$F_c=\frac{m{v}^2}{r}=\frac{7}{10}\times \frac{40}{7}\times \frac{40}{7}=\frac{160}{7}N$