A 2m radius uniform 50kg disk has an object of unknown moment of inertia screwed into its center. A constant external force of 200N is applied tangentially to the disk's rim. A constant torque due to kinetic friction of 180Nmrad is present throughout the motion. The system angularly accelerates from 10RPM to 60RPM in 10secs.
Find the angular acceleration in rad/s^2 and the moment of inertia of the object about an axis through the disk's center.
Find the angular displacement for the 10sec interval.
Find the angular momentum at 10sec for the system.
Find the rotation power for both friction and external force at t = 2 sec
I can understand how torque can have units of Newton-meters (Nm) but not Newton-meter-radians or Newton-milliradians. What does Nmrad mean?
Use the two rpms and the 10 second interval to get the angular acceleration in rad/s^2. Call it alpha
Once you know the torque T, use
T = I * alpha
to get the moment of inertia, I .
The net torque T i the difference between the applied torque and the frictional torque
The angular displacement during the 10 second interval is the average angular speed (35 rpm converted to radians/s). multiplied by 10 s.
Angular momentum is I * w
where w is the angular speed. At 10 s, it is 60 rpm, converted to rad/s.
That should get you started. Show your work for further assistance, if needed.