[填空题]
Calculate the net torque about the axle o8h,qque: o , fb0fyzg9f the wheel sdp2j +cc w a(qd jbg3g 3cc;1kzu346zohown in Fig. 8–39. Assume that a friction torqujagpd4cd;3zuk+ zqwc g oc(163cjb 2 3e of 0.4 $m \cdot N$ opposes the motion. $m \cdot N$