[填空题]
The bolts on the cylinder hea9; vv u9rzm7rwz*e9yh d oxpwdo2i.21d(y 8 o yz:otin.e.e5w qtlh1zy3f an engine require tightening to a torque of 38 wt q..(o 1p .n:1xo8zed3dywii22 eoy y5tlzh$m \cdot N$ If a wrench is 28 cm long, what force perpendicular to the wrench must the mechanic exert at its end? N If the six-sided bolt head is 15 mm in diameter, estimate the force applied near each of the six points by a socket wrench (Fig. 8–41). N