The Torque to Overcome Friction, Tfriction
Rotation and Friction
There is nothing different in the behavior of friction due to the differences between linear and rotational motion—friction is friction—but how it is taken into account does differ, since friction will appear as a torsional rather than linear resistance to movement. Some component of the total torque applied to rotate an object will be the torque needed just to overcome friction, and this component, Tfriction, is found in the rotational version of the formula used to estimate the maximum power needed by a given effect:
Pmax = (Taccel + Tfriction + Tlifting) ωmax
There is also nothing about rotational motion that negates the complexity involved in accurately predicting friction. ...