When a ship sails from salt water into fresh water, the fraction of its volume above the water surface will

When a ship sails from salt water into fresh water, the fraction of its volume above the water surface will decrease. This is due to the principle of buoyancy, which states that the buoyant force acting on an object is equal to the weight of the fluid displaced by the object. In other words, the more fluid an object displaces, the greater the buoyant force it experiences. Salt water is denser than fresh water, which means that a ship will displace more water (and hence experience a greater buoyant force) in salt water than in fresh water. Therefore, when a ship sails from salt water into fresh water, the buoyant force acting on it decreases. However, the weight of the ship remains the same regardless of whether it is in salt water or fresh water. Therefore, when the buoyant force acting on the ship decreases, the ship sinks slightly deeper into the water, and the fraction of its volume above the water surface decreases. Therefore, the fraction of the ship's volume above the water surface will decrease when it sails from salt water into fresh water.