[填空题]
The bolts on the cylinder head of an engw.cjdy /z 1vyfje3 :1kine require tighteninf)uu+aoq .c*x g to a torque of 38 a+*u.qfcuox) $m \cdot N$ 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