A disk of mass m1 and radius R1 is rotating about the center around a thin axle with an initial angular velocity of ω. A second disk of mass m2 and radius R2 is initially stationary and rides on the similar axle as m1. The second mass is then lowered thus that it contacts the first mass. At some final time, both masses are rotating with a new angular velocity ωf.
a) Evaluate the initial angular momentum of the system?
b) Evaluate the final angular momentum?
c) Calculate the final angular velocity ωf?