The tower crane shown is modeled below the photo. The horizontal boom is pivoted at A, which is behind the operator's cab in the picture. The permanently attached cables at B make a 15 angle with the boom. The horizontal distance between A and B is 80 ft. The load carriage C can move along the 120-ft long boom, which is assumed weightless. Calculate the reactions at A for a 10,000-lb vertical load on carriage 'C' at the position Xc= 120 ft. Also calculate the shear and bending moment in the boom at XD = 50 ft assuming that the boom is a homogeneous beam. pulley A TAB XD 15 -80 ft -xc A cab X B 15 D 10,000 lb B C