Q. A sphere of mass $0.5\ kg$ and diameter $1m$ rolls without sliding with a constant velocity of $5\ m/s$, calculate what is the ratio of the rotational $K.E.$ to the total kinetic energy of the sphere
A) $\frac{7}{10}$
B) $\frac{5}{7}$
C) $\frac{2}{7}$
D) $\frac{1}{2}$
Explanation
(c) $\frac{K_{R}}{K_{N}} = \frac{K^{2}/R^{2}}{1 + K^{2}/R^{2}} = \frac{2/5}{1 + 2/5} = 2/7$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.