Q. Ratio of total kinetic energy and rotational kinetic energy in the motion of a disc is
A) 1:1
B) 2:7
C) 1:2
D) 3:1
Explanation
(d) $\frac{Total\ kinetic\ energy}{Rotational\ kinetic\ energy}$
$= \frac{\frac{1}{2}mv^{2}\left( 1 + \frac{K^{2}}{R^{2}} \right)}{\frac{1}{2}mv^{2}\frac{K^{2}}{R^{2}}\ } = \frac{1 + \frac{K^{2}}{R^{2}}}{\frac{K^{2}}{R^{2}}} = \frac{1 + \frac{1}{2}}{\frac{1}{2}} = \frac{3/2}{1/2} = 3$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.