[填空题]
A person exerts a force du 57 k/nd.(q*3qet psi -wuv(idhrw qqtm*60of 55 N on the end gyhx *l xj*.5cof a door 74 cm wide. What is the magnitude of the torque if the force is exertedxch jxlg 5y.** (a) perpendicular to the door $m \cdot N$ (b) at a 45 $^{\circ} $ angle to the face of the door? $m \cdot N$