[问答题]
Two blocks, each of mass m, euo3 +slo c92uarf.e((qu g541l onoi ade attached to the ends of a massless rod which pivots as shown in Fig. 8–40. Initially the rod is held in the horizontal position and then relfo(4e5ga(odn uqi1 . leased. Calculate the magnitude and direction of the net torque on this system.