Calculate the magnitude of the normal force on a 17.7 kg block in the following circumstances. (Enter your answers in N.) HINT (a) The block is resting on a level surface. 173.46 The four cases in this problem are the most common situations. In general, solving for the normal force involves drawing a free-body diagram and applying Newton's second law. N (b) The block is resting on a surface tilted up at a 20.8 angle with respect to the horizontal. 162.16 N (c) The block is resting on the floor of an elevator that is accelerating upward at 4.53 m/s. 253.64 N (d) The block is on a level surface and a force of 115 N is exerted on it at an angle of 20.8 above the horizontal. 214.3 XN