[填空题]
The bolts on the cyl9 q8z valt.o1v: to:wro a9kku rg-+fbx+w-z5inder head of an engine require tightening to a torque of 38:arfxz-br wo5outk-k +w+g :9 $m \cdot N$ 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