Consider an object at rest, completely immersed in a fluid. It displaces an equal volume of fluid to occupy that space. An upward buoyant force keeps the object stationary. If the object is removed from the fluid, the space gets filled by the same volume of fluid earlier displaced by it. This fluid volume is now acted upon by the same buoyant force earlier acting on the object. Since the fluid volume is at rest, the buoyant force is balanced by its weight. Thus, the magnitude of the buoyant force acting on an object in a fluid equals the weight of the fluid displaced by it. This is known as Archimedes' Principle. Mathematically, the buoyant force is equal to the product of mass of the fluid displaced and the acceleration due to gravity. Using the relationship between mass and density, the buoyant force can also be represented as the product of density of fluid, volume of displaced fluid, and the acceleration due to gravity.