Q. The moment of inertia of wheel about the axis of rotation is 3.0 MKS units. Its kinetic energy will be 600 J if period of rotation is
A) 0.05 s
B) 0.314 s
C) 3.18 s
D) 20 s
Explanation
(b) As $E = \frac{1}{2}I\omega^{2}$
$\omega = \sqrt{\frac{2E}{I}} = \sqrt{\frac{2 \times 600}{3.0}} = 20$
$\omega = \frac{2\pi}{T} = 20,\ T = \frac{2\pi}{20} = \frac{\pi}{10} = 0.314\ s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.