It's that time of the year  when Brian loves to decorate his house by hanging up festive Christmas lights. To hang up his lights, he leans the top of a 5.2-m ladder against the side of his house; the bottom of the ladder is 1.8 m away from the house. Suppose the CM of the ladder is located 2.2 m from the base of the ladder, as measured along its length. Brian is standing 3.5 m from the base of the ladder, also measured along its length. The mass of the ladder is 12.0 kg and Brian's mass is 81.2 kg. Note: Use g = 9.8 m/s². If friction at the top of the ladder is ignored, determine the normal force at the bottom of the ladder?