Serway & Jewett — Angular Momentum: Problem 23

A 60.0-kg woman stands at the western rim of a horizontal turntable having a moment of inertia of \(500\text{ kg}\cdot\text{m}^2\) and a radius of \(2.00\text{ m}\). The turntable is initially at rest and is free to rotate about a frictionless, vertical axle through its center. The woman then starts walking around the rim clockwise (as viewed from above the system) at a constant speed of \(1.50\text{ m/s}\) relative to the Earth. Consider the woman–turntable system as motion begins. (a) Is the mechanical energy of the system constant? (b) Is the momentum of the system constant? (c) Is the angular momentum of the system constant? (d) In what direction and with what angular speed does the turntable rotate? (e) How much potential energy in the woman’s body is converted into mechanical energy of the woman–turntable system as the woman sets herself and the turntable into motion?