Q. A body rolls down an inclined plane. If its kinetic energy of rotation is 40% of its kinetic energy of translation, then the body is
A) Solid cylinder
B) Solid sphere
C) Disc
D) Ring
Explanation
(b) $\frac{1}{2}I\omega^{2} = 40\%\ of\frac{1}{2}mv^{2}$
$\frac{1}{2}\ I\omega^{2} = \frac{40}{100}\left( \frac{1}{2}mr^{2}\omega^{2} \right)$
$I = \frac{2}{5}mr^{2}$
So, the body is solid sphere.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.