[填空题]
A person exerts a force *7t4tpi pywt 2;vwg)jr ev1l9of 55 N on the end of a door :c.t tug,hf1m 74 cm wide. What is the magnitude of the t.cgf uh1,mtt:orque 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? $m \cdot N$