There's a question that I'm having trouble with that I do not know exactly how to set up. Here it is..... A 320g mass and a 400g mass are attached to the two ends of a string that goes over a pulley with a radius of 8.70 cm. Because of friciton, the pulley does not begin to rotate. What is the magnitude of the frictional torque on the bearing of the pulley if the system is in static equilibrium. Can someone help, I know since it's in static equlibrium that the sum of Fy=0 and sum of torque = 0.