[填空题]
The bolts on the cylinder head of an z e+.9p t. ihva3l4 tpav5pb9dengine require tightening ty,6nnu(k dz /s /s.0f 1lyn tqm3(tisco a torque of 38 f(lnkus/tnym yn / 6qsc3s,t10i d(.z$m \cdot N$ 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