Kelluvuuden

Kelluvuuden is the Finnish term for buoyancy, the upward force that a fluid exerts on a partially or fully submerged body. In physics, it describes the tendency of an object to float in a liquid or gas and is often discussed as the buoyant property or floatability of an object in a fluid.

The principle behind kelluvuuden is Archimedes’ principle: the buoyant force equals the weight of the displaced fluid, B = ρ_fluid × g × V_submerged, where ρ_fluid is the fluid density, g is the acceleration due to gravity, and V_submerged is the volume of the object immersed. An object sinks or rises depending on how its average density compares with the surrounding fluid. If the object’s density is less than the fluid’s, kelluvuuden is positive and the object tends to float; if densities are equal, it experiences neutral buoyancy; if greater, it sinks.

Practical applications include ship and boat design, where hull shape and displacement maximize flotation; submarines and ballast systems that control depth; and flotation devices such as life jackets and buoys. Kelluvuuden also informs environmental and biological contexts, such as the behavior of sediments, aquatic organisms, and floating debris.

In Finnish science communication, kelluvuuden is discussed alongside related concepts such as density, specific gravity, and buoyant force. The concept has ancient origins in Archimedes’ work and remains fundamental to hydrostatics and fluid dynamics, with ongoing relevance in engineering, oceanography, and materials science.