question_answer

If \[\mu \] is the actual coefficient of friction in a belt moving in grooved pulley, the groove angle being \[2\alpha ,\] the virtual coefficient of friction will be:

A) \[\frac{\mu }{\sin \alpha }\]                    

B) \[\frac{\mu }{\cos \alpha }\]

C) \[\mu \sin \alpha \]                     

D) \[\mu \cos \alpha \]