[20p] In the gure below, the horizontal force [41 maintains the block at rest on the frictionless inclined plane. The mass of the block is 5.0 kg and the angle 8 is 30\". (a) [5p] What is the magnitude of I? ? {b} [5p] What is the magnitude of the normal force? (it) [10p] If we stop neglecting the friction between the block and the inclined plane and we assume the coefficient of static friction between the two is 0.45? what is the magnitude of I? that maintains the block at rest