Two Rotating Disks Problem

A system consists of two small disk, of masses m and 2m, attached to a rod of negligible mass of length 3t as shown. The rod is free to turn about a vertical axis through point P. The two disks rest on a rough horizontal surface' the coefficient of friction between the disks and the surface is m. At time t = 0, the rod has an initial counterclockwise angular velocity wo about P. The system is gradually brought to rest by friction. Develop expressions for the following quantities in terms of m, m, l, g and wo.

A) The initial angular momentum of the system about the axis through P

B) The frictional torque acting on the system about the axis through P.

C) The time T at which the system will come to rest.