Answer :
Final answer:
The correct answer is B. 62.4 pounds per cubic foot. This value is related to the density of water and is used to calculate buoyancy in fluids like freshwater and saltwater.
Explanation:
Pure water at sea level weighs 62.4 pounds per cubic foot. This is a well-known and standardized value used in various calculations involving fluid dynamics and is particularly relevant within the fields of engineering and physics where the properties of water are significant. When it comes to how much of an object will be submerged in water, the key principle is Archimedes' principle, which states that the buoyant force on a submerged object is equal to the weight of the fluid that is displaced by the object.
As an example, a human body with a density of 995 kg/m³ would be almost completely submerged in freshwater, which has a density of 1,000 kg/m³. When it comes to saltwater, which has a higher density of 1027 kg/m³, a smaller fraction of the body would be submerged, because the buoyant force would be greater, while the body's weight remains the same.