Q. A solid sphere is rolling without slipping on a horizontal plane. The ratio of the linear kinetic energy of the centre of mass of the sphere and rotational kinetic energy is :
A) $\frac34$
B) $\frac43$
C) $\frac52$
D) $\frac25$
Explanation
[Solution by Dr. Abubacker] Linear KE $=\frac12mv^2$; rotational KE $=\frac12\left(\frac25mr^2\right)\left(\frac vr\right)^2=\frac15mv^2$. Ratio $=\frac{1/2}{1/5}=\frac52$. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.