OnlineCBT
Physics · SYSTEMS OF PARTICLES AND ROTATIONAL MOTION
हिन्दीA solid sphere and a solid cylinder have equal mass and equal radius. If they are rotated about their respective axes of symmetry (diameter for the sphere, central axis for the cylinder) with the same angular momentum \( L \), the ratio of the rotational kinetic energy of the sphere to that of the cylinder is:
Correct answer · Option 3
5 : 4
Explanation
\( K = \frac{L^2}{2I} \). For solid sphere, \( I_s = \frac{2}{5}MR^2 \). For solid cylinder, \( I_c = \frac{1}{2}MR^2 \). Thus \( K_s / K_c = I_c / I_s = \frac{1/2}{2/5} = \frac{5}{4} \).
