[填空题]
The bolts on the cylinder head of an engine require tu*); wxp2mph6 iuum te65vzr*7ofzn8 ightening 71 -d:iopsccahksg0 ;to a torque of 38hkd;7:oic asc-0 g1sp $m \cdot N$ 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