[填空题]
Calculate the net torqu84 *x/mm4r9j8y r /h/0xhva zpo4et-uxmcz kqef;srpa c-9ekeu 40 pf ;cs7fe0 about the axle of the wheel shown in Fig. 8–39. Assume that a frictefe4 s-7p;s pkr 0;cc9aue 0ffion torque of 0.4 $m \cdot N$ opposes the motion. $m \cdot N$