Question

Moment of inertia of wheel about the axis of rotation is 3 MKS units. Its kinetic energy will be $600J$, if period of rotation is (in seconds)

• A. $\pi$
• B. $\frac{\pi }{5}$
• C. $\frac{\pi }{10}$
• D. $2\pi$

Answer 1

Answer: (C)

$\frac{\pi }{10}$

$E=\frac{1}{2}l{\omega }^2$

$\omega =\sqrt{\frac{2E}{l}}-\sqrt{\frac{2\times 600}{3}}=20$

$\omega =\frac{2\pi }{T}=20\Rightarrow T=\frac{\pi }{10}$