[问答题]
Two blocks, each of mass m, 8vq7b :cf fhj0areq-bz mo09 bbij-;v; mi2zm,r g attached 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. Calcuv ,g bmzm;0i;mjorb- b-zq i92late the magnitude and direction of the net torque on this system.