[填空题]
The bolts on the cylinipgwch h* oiz* (kh9l*4kdv7t2d*+ gw der head ofg 5:(bg6ttqd;yn) w co an engine require tightening to a torque of 38(5tgq;ngcwb6:toy) d $m \cdot N$ 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