[填空题]
The bolts on the cylinder head of an engine 9 q 2si,b5qr5rt kj/vmre)jey -g.bj vjx 0r7z;iquire tightening to a torque of 38 j;b) .v0ji yjxge-r7z $m \cdot N$ 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