The provided expression, P = P0 + pgh, represents the variation of pressure with depth in a fluid. Here P is the pressure at a certain depth, P0 is the pressure at the surface of the fluid, p is the fluid density, g is the acceleration due to gravity, and h is the depth measured from the surface downwards.
Option 1: This expression is associated with Pascal`s law. Pascal`s law states that when pressure is applied to a fluid in a closed system, it gets transmitted uniformly throughout the fluid in all directions. In the provided expression, the pressure at any depth is given by P0 + pgh, which is consistent with Pascal`s law.
Option 2: Newton`s law is not directly related to the given expression. Newton`s laws of motion deal with the relationship between an object`s motion and the forces acting upon it.
Option 3: The given expression does not represent Bernoulli`s principle. Bernoulli`s principle describes the relationship between the pressure, velocity, and elevation in a flowing fluid.
Option 4: Likewise, the given expression does not correspond to Archimedes` principle. Archimedes` principle relates to the buoyant force experienced by an object immersed in a fluid.
Therefore, the correct answer