The simulation of a rotating wheel below shows the relationship between net torque on the wheel and its angular acceleration.  The center of the wheel is fixed so that the net external force on the wheel remains zero.

If two external forces, one at r=0.5 m and one at 1m, exert zero net torque on the wheel, what is the ratio of the magnitudes of the forces?

Suppose a 1-N force acts at r=1 m and a 2-N force acts at r=0.5 m in the same direction as the 1-N force.  What is the net torque on the wheel?

 

St = Ia

F1 N    r1 m

F2 = N    r2 m