[问答题]
Two blocks, each of mass m,g 5b-j62+mc .brrnzntvwnl+ 4 are attached to the ends of a massless rod wh-mxl3mp36i mgich pivots as shown in Fig. 8–40. Initially the rod is held in the horizontal position and then releasedlm-3g3 6imxp m. Calculate the magnitude and direction of the net torque on this system.