Final answer:
After adding salt to the water, the density of water increases resulting in an increased buoyant force. Due to Archimedes' Principle, the wooden block floats higher in the salt water than in fresh water.
Step-by-step explanation:
When salt is added into the water, it dissolves and increases the density of the water. This phenomena is due to the spheres of hydration that form around the ions when salt (NaCl) is mixed in water. As the water becomes denser, the buoyant force exerted by the water on the wooden block also increases. As a result, the wooden block will float higher in the salt water than in the fresh water. More of the block will be visible above the water due to increased buoyancy. The floatation of the block is determined by Archimedes' Principle, which states that the upward buoyant force exerted on a body immersed in a fluid is equal to the weight of the fluid that the body displaces. So, as the density of the water increases, it displaces more weight resulting in an increased buoyant force that makes the wooden block float higher.
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