[填空题]
The bolts on the cylu)rkx0dzr ; f2ji q v*amwp;y,.3p2a iinx 9d1z1 eqk.qu:ewym7der head of an engine require tightening to a torque of 38 .1 mduwqkze1q:7yxe9 $m \cdot N$ 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