[填空题]
The bolts on the cylinder head of an engine require tightisa 8) wtf+v4w w2igq(ening to a torque o8w52gvac-b 6,*0bs6pv+avzh mz eihkf 38m+zi6a6b bhpva h08c*, 25 kzvs gv-we $m \cdot N$ 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