Two disks of identical mass however different radii (r and2r) are spinning on frictionless bearings at the same angular speed ω0, but in opposite directions. The two disks are brought slowly together. The resulting frictional force among the surfaces eventually brings them to a common angular velocity.
1) What is the magnitude of that final angular velocity in terms of ω0? (Utilize the following variables as necessary: omega_0 for ω0.)
2) What is the change in rotational kinetic energy of the system? (Take K as the initial kinetic energy.)