[问答题]
Two blocks, each of vc1b9e 8uy. ozmcg49pmass m, are attached to the f:*ka6h 9 csbbends of a massless rod which pivots as shown in Fig. 8–40. Initially the rod is held in the horizontal position and then released. Calculate the magnitude and direction of the net torque on this systbfbc9*h6as: kem.