posted by Catherine .
A beam, B1, of mass M1 = 0.6887 kg and length L1=1 m is pivoted about its lowest point at P1. A second beam, B2, of mass M2=0.200 kg and length L2=0.200m is suspended (pivoted) from B1 at a point P2, which is a horizontal distance d=0.550, from P1. To keep the system at equilibrium, a mass m =0.500kg has to be suspended from massless string that runs horizontally from P3, at the top of beam B1, and passes over a frictionless pulley. The string runs at a vertical distance y = 0.707 m above the pivot point P1. Determine the net torque at P1, P2, and P3.