(5) The 12 lb uniform disk has a radius of 4 ft and is supported as shown by a smooth vertical wall B and a rough inclined wall 4. A 60 lb block is mounted on the disk at the midpoint between center C and wall B. If the disk does not slip and remains in equilibrium, determine the friction force 2ft 2ft on wall 4 and the normal forces from the contact surfaces at C : B A and B. Ans: NB = 146 1b, NA = 160 1b, F. = 30 1b