[问答题]
Two blocks, each of mass :7xn((usbj)ug4lv ip m, are attached to the endsru ; * g:xelf87c z1seuyh7s4n of a massless rod which pivots as shown in Fig. 8–40. Init4r1*u u sx;eg y7:hsz87 elcnfially the rod is held in the horizontal position and then released. Calculate the magnitude and direction of the net torque on this system.
