Disk under torque

A solid disk has M=2.0 kg, R=0.50 m, and I=(1/2)MR^2=0.25 kg m^2. A 4.0 N tangential force acts at the rim, giving torque=rF=2.0 N m.

1. Torque is perpendicular lever arm times force.
2. alpha=torque/I.
3. Keep rotational units.