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.[1]

Explanation

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

principle

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...