Archimedes' Principle: Archimedes' Principle is a fundamental principle of physics, particularly in fluid mechanics. It was formulated by the ancient Greek mathematician and scientist Archimedes of Syracuse. The principle states that when an object is immersed in a fluid (either liquid or gas), it experiences an upward buoyant force that is equal to the weight of the fluid that the object displaces. In simpler terms, the buoyant force on an object submerged in a fluid is equal to the weight of the fluid it displaces.