A solid cylinder of mass and radius is rotating freely about its symmetry axis at
PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Energy and Momentum of Rotating Systems · Energy and Momentum of Rotating Systems
Problem
A solid cylinder of mass 1.5kg and radius 0.20m is rotating freely about its symmetry axis at 40rads−1. A thin circular ring of the same mass and radius is gently dropped coaxially onto the cylinder so that they stick together and rotate as one body without external torque.
(i) Calculate the initial rotational kinetic energy of the system.
(ii) Determine the common angular speed immediately after they couple.
(iii) Find the percentage loss in rotational kinetic energy due to coupling.