Three objects, A: (a solid sphere), B: (a thin circular disk) and C: (a circular ring), each have the same mass M and radius R. They all spin with the same angular speed ω about their own symmetry axes. The amounts of work (W) required to bring them to rest, would satisfy the relation

Question

Accepted Answer

(1) W_C>W_B>W_A. Given: solid sphere, disk and ring, all of mass M and radius R, all spinning at ω about their symmetry axes. Idea: the work needed to stop a body equals its kinetic energy, W=1/2Iω², and M, R and ω are the same for all three — so only I separates them. I_A=2/5MR²=0.4MR² I_B=1/2MR²=0.5MR² I_C=MR² I_C>I_B>I_A, so W_C>W_B>W_A.

Three objects, A: (a solid sphere), B: (a thin circular disk) and C: (a circular ring), each have the same mass M and radius R. They all spin with the same angular speed ω about their own symmetry axes. The amounts of work (W) required to bring them to rest, would satisfy the relation

Step-by-step solution

Why the other options are wrong