A solid cylinder (the moment of inertia about its axis is mr²/2) rolls without slipping. The ratio of its rotational to translational kinetic energy is A) 1/4. B) 1/2. C) 1. D) 2. E) 4.

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Quizplus · Accepted Answer

For a rolling object, the rotational kinetic energy is (1/2)Iω² and the translational kinetic energy is (1/2)mv². For a solid cylinder, I = (1/2)mr² and v = rω, so the ratio of rotational to translational kinetic energy is (1/2)(1/2)mr²ω² / (1/2)mv² = 1/2.

A Solid Cylinder (The Moment of Inertia About Its Axis