at P , and α is the angle between F and the radius vector OP ; φ + α = ° . The torque due to F about the origin is OP × F . Now OP = OC + OP . [Refer to Fig.
. (b).] Since OC is along the axis, the torque resulting from it is excluded from our consideration. The effective torque due to F is τττττ = CP × F ; it is directed along the axis of rotation and has a magnitude τ = r F sin α , Therefore, d W = τ d θ If there are more than one forces acting on the body, the work done by all of them can be added to give the total work done on the body. Denoting the magnitudes of the torques due to the different forces as τ , τ , … etc, ...)d W Remember, the forces giving rise to the torques act on different particles, but the