[填空题]
A person exerts a force of 5 vhm62lbshl/,rh zx* 55 N qodu v0ka:;,oon the end of a door 74 cm wide. What is the magnitude of the torque if theo: oq au,0d;kv force is exerted (a) perpendicular to the door $m \cdot N$ (b) at a 45 $^{\circ} $ angle to the face of the door? $m \cdot N$