[问答题]
Two blocks, each of mass m, are attag.:mypwwo;u m; 9 ,je+w+gdzf r;a+ws fq n*3,lfrnt5faqx8 /ched to the ends of a massless rod which pivots as shown in Fig.ql+;f*f sr5/a, n w8xrtnf3a q 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 system.