[问答题]
Two blocks, each of mass m, a g-a ixs: 4)d9vxpudn,re attachedd-yipr:i6k8,os /5pjx .h.o m ;qgcnq 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 dirdsj,-pqoyik ogm5 .px86; /:rhci.qn ection of the net torque on this system.