What is buoyancy

Buoyancy is the ability of bodies to stay on the surface of a liquid or in the air without sinking. It is a fundamental physical principle governed by Archimedes’ Principle, enunciated by the Greek scientist of the same name.

Archimedes’ principle. Buoyancy force

Archimedes’ principle is a physical law established by the Greek scientist Archimedes, which describes the behavior of bodies immersed in fluids, either liquids or gases. This principle states that a body fully or partially immersed in a fluid will experience a vertical and upward thrust equal to the weight of the fluid displaced by the body. When a body is immersed in a fluid, either completely or partially, the fluid exerts a pressure on the body in all directions. The thrust is the resultant force of all these pressures and is equal to the weight of the fluid displaced by the body. If the weight of the object is less than the thrust, the body will float. If the weight is greater, the body will sink.

Relationship between buoyancy and density

Density is a physical property that relates the mass of an object to its volume, in the SI it is expressed in kilograms per cubic meter (kg/m³). It is a key factor in understanding buoyancy, as it determines whether an object sinks or floats when immersed in a fluid. This relationship is fundamental in the study of Archimedes’ principle and therefore, knowing the density of materials allows us to predict their behavior in water or other fluids.

Applications of the buoyancy principle

The principle of buoyancy is applied in many areas, such as ship design and construction. In the case of ships, for example, the shape and volume of the hull allows enough water to be displaced so that the total weight of the ship is less than the thrust generated by the water, thus ensuring its buoyancy.

The online buoyancy simulations on this page are an excellent tool to learn more about this important physics concept, to know Archimedes’ principle and to understand the relationship between buoyancy and density. Don’t miss them!