6-71. The boat has a weight of 2300 lb and a center of gravity at G. If it rests on the trailer at the smooth contact A and can be considered pinned at B, determine the absolute maximum bending stress developed in the main strut of the trailer. Consider the strut to be a box-beam having the dimensions shown and pinned at C. SEA SPRITE A B G [1 ft C 3 ft 5 ft -4 ft- 1 ft 1.75 in. 3 in. 1.75 in 1.5 in.