[问答题]
Two blocks, each of mass m, are attached to th:oecb( g sei,gov8g: tvb )./je ends of a massless rod whi+db7 w ncnq0o y38rqu:4zs6 kmch pivots as shown in Fig. 8–40. Initially the rod is held in the horizontal position and then rdq7cu m6 8kzs:r+ b nq3yonw04eleased. Calculate the magnitude and direction of the net torque on this system.