The large disk-shaped flywheel illustrated below has a radius R of 0.25 m. It is made to spin by the small wheel that contacts it at its rim. The small wheel applies a constant force of 1430 N. Friction in the bearing exerts a retarding torque 22 Nm on the large wheel. If the magnitude of the angular acceleration of the large wheel is 145 rad/s2, what is its mass?

Answer 1

So first calculate the total torque.
T1 is given = -22
T2 can be found using T=Fr
T=1430(.25)= 357.5
Total T= 335.5Nm
Then use T=Ia to get the moment of inertia
335.5=I (145)
I= 2.31
For a solid cylinder/disk, the moment of inertia is given by I=1/2mr^2
2.31=1/2m(.25)^2
m=73.9kg