[填空题]
A person exerts a forc:g*5;:ryk*aby 0 bvsh7u, zm hu)zyyue of 55 N on the end of a doo-22d u/abu pnayk,lq/j,l/qj r 74 cm wide. What is the magnitude of the torque if the force isla dq/2upjj k/2l-qb, /uny a, exerted (a) perpendicular to the door $m \cdot N$ (b) at a 45 $^{\circ} $ angle to the face of the door? $m \cdot N$