1 (30%) The low-bed trailer (拖車）shown is designed so that the rear end of the bed can be lowered to ground level in order to facilitate the loading of wrecked vehicles (使易於放下廢車)A 1500 kg vehicle has been hauled (拖運）to the position shown by a winch (絞車)；the trailer is then returned to a traveling position where a = 0 and both AB and BE arc horizontal. Considering the weight of the disabled automobile (廢車)， determine the force which must be exerted by the hydraulic cylinder of CD to maintain a position with a = 0.