[填空题]
The bolts on the cylinder head of an ejv p: +oxi*b3lngine require tightening tok.cp4 ;zk6 ypoe2+ ubf a torque of 38 6fzp y2+copbk4k.u e;$m \cdot N$ 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