A certain ship is shaped like a box, with vertical sides and a flat bottom. When the ship sails with cargo in the ocean (saltwater), it rides on the water with some of the hull underwater. When the ship enters a fresh water river, it will ride slightly lower in the water. Then the ship's cargo (Mc = 9.49x105 kg) is removed while the ship is in fresh water, and the ship rides at the same height as it did in the saltwater. Find the mass of the ship without the cargo.