Archimedes' principle is a law of physics stating that the
upward buoyant force exerted on a body immersed in a fluid
is equal to the weight of the fluid the body displaces. In other
words, an immersed object is buoyed up by a force equal to
the weight of the fluid it actually displaces. Archimedes'
principle is an important and underlying concept in the field
of fluid mechanics. This principle is named after its
discoverer, Archimedes of Syracuse.
Archimedes' two-part treatise on hydrostatics, called On
Floating Bodies, states that:
Any object, wholly or partially immersed in a fluid, is
buoyed up by a force equal to the weight of the fluid
displaced by the object.
— Archimedes of Syracuse
with the clarifications that for a sunken object the volume of
displaced fluid is the volume of the object. Thus, in short,
buoyancy = weight of displaced fluid. Archimedes' principle
is true of liquids and gases, both of which are fluids. If an
immersed object displaces 1 kilogram of fluid, the buoyant
force acting on it is equal to the weight of 1 kilogram
(technically, as a kilogram is unit of mass and not of force, the buoyant force is the weight of 1 kg, which is 9.8
Newtons.) It is important to note that the term immersed refers to an object that is either completely or partially
submerged. If a sealed 1-liter container is immersed halfway into the water, it will displace a half-liter of water and
be buoyed up by a force equal to the weight of a half-liter of water, no matter what is in the container.
Archimedes (287 BC - 212 BC), the discoverer of this
If such an object is completely immersed (submerged), it will be buoyed up by a force equivalent to the weight of a
full liter of water (1 kilogram of mass). If the container is completely submerged and does not compress, the buoyant
force will equal the weight of 1 kilogram of water at any depth. This is due to the fact that at any depth, the container
can displace no...