Objects submerged at rest in a fluid are subject to pressure forces from the fluid. The more deeply submerged the object is, the greater the force. The net force, or buoyant force, points in the upward/ toward the surface direction and acts through the center of gravity of the object, also known as the center of buoyancy. Since the object is nonspecific, it is helpful to take an object of a given size composed of the fluid material. Then, since the object is at rest, the buoyant force must be equal in magnitude to the weight of the fluid displaced by the object. This result is known as Archimedes' Principle.
Example:
Consider a system consisting of a block submerged in water and connected to a spring scale in order to measure the buoyant force.
If the block has volume V then the buoyant force is B where is the density of water.
