[问答题]
Two blocks, each of mass m, arethafe (1isyr 1l ct/-) attacmseyj ,wc1c5zu : 0x,khed 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 released. Calculate the magnitude and direction of the net torque on this syste cwxy, jucm:1es,k50zm.