[填空题]
A person exerts a force of 55 N on the end, 0ghgsfz/m*d of v vlob+ cjr+8(a door 74 cm wide. What is the magnitude of the tor ( o++lvrvcjb8que if the force is exerted (a) perpendicular to the door $m \cdot N$ (b) at a 45 $^{\circ} $ angle to the face of the door? $m \cdot N$