[问答题]
Two blocks, each of mass m, are attah t v/,770xul4 k3(sgdz hpykwched ta-ys9d1ivvi - wtv1o.o the ends of a massless rod which pivots as shown in Fig. 8–40. Initially the rod is held in the horiswvavi1o1it yv-9 d.-zontal position and then released. Calculate the magnitude and direction of the net torque on this system.
