[填空题]
The bolts on the cylue:ue5o3 v3*wr sj :;jhb sx8gintqd r sob/ qde .k3xn9s( 5ahr m/z8l20nev)d-der head of an engine require tightening to a torque of 38 9kmdqerhznq.dor/vasb0s n5)t le/-(xd2 8 3$m \cdot N$ 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