Q. A sphere of mass $50\ g$ and diameter $20\ cm$ rolls without slipping with a velocity of $5cm/sec$. Its total kinetic energy is
A) $625\ erg$
B) $250\ erg$
C) $875\ erg$
D) $875\ joule$
Explanation
(c) $K_{N} = \frac{1}{2}mv^{2}\left( 1 + \frac{K^{2}}{R^{2}} \right) = \frac{1}{2} \times 50 \times (5)^{2} \times \left( 1 + \frac{2}{5} \right)$
$= 875erg$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.