Buoyancy tersely: Buoyancy = weight of displaced fluid. Archimedes' principle does not consider the surface tension (capillarity) acting on the body, but this additional force modifies only the amount of fluid displaced and the spatial distribution of the displacement, so the principle that "Buoyancy = weight of displaced fluid" remains valid. The weight of the displaced fluid is directly proportional to the volume of the displaced fluid (if the surrounding fluid is of uniform density). In simple terms, the principle states that the buoyancy force on an object is equal to the weight of the fluid displaced by the object, or
Buoyancy aid should detail: For a buoyancy aid to be sold in the European Union, it must be C.E. tested and approved. Buoyancy aids with providing only 50 N of force should only be used by swimmers in sheltered waters when help is close at hand. They are not guaranteed to turn a person from a face-down position in the water. The foam used in buoyancy aids does degrade with age. Manufacturers add additional foam to ensure that their buoyancy aids will still provide enough force even after years of use. A rough life expectancy is three years of use, although buoyancy