To which part of physics does the Archimedes' Principle refer?

To which part of physics does Archimedes' Principle refer? It refers to buoyancy.

The principle states that an object partially or completely immersed in a fluid experiences an upward force equal to the weight of the fluid it displaces. That upward force is called buoyancy, or upthrust. The fluid may be a liquid such as water or a gas such as air.

Buoyancy explains why ships float, why a swimmer feels lighter underwater, and why hot-air balloons rise. Whether an object sinks or floats depends on the relationship between its weight and the buoyant force. An object rises when buoyancy exceeds its weight, sinks when its weight is greater, and remains in equilibrium when the two forces balance.

The principle is named after Archimedes of Syracuse, the ancient Greek mathematician and scientist. It is closely associated with fluid mechanics and hydrostatics, but "buoyancy" is the standard quiz answer to this wording. A common misconception is that only floating objects experience buoyancy; fully submerged objects also experience the force, even when it is not strong enough to keep them afloat.