Rotational kinetic energy and rolling motion

Learning objectives

Calculate rotational kinetic energy as ½Iω² and the total kinetic energy of a rolling body as the sum of its translational and rotational kinetic energies

Calculate the work done by a constant torque as W = τΔθ and the power delivered by a torque as P = τω

Apply conservation of energy to a body rolling without slipping down an incline, and explain why a hoop, a solid cylinder and a solid sphere of equal mass and radius arrive with different speeds

Explain why static friction does no work on a body that rolls without slipping, and how the energy analysis changes if the body slips

Predict and justify, using energy reasoning, the outcome of a race between rolling bodies whose mass distributions differ