What are the applications of the Archimedes Principle

Archimedes' law / principle

We deal with Archimedes' principle in this article on physics. Archimedes' law is discussed and an example is shown. This article belongs to our mechanics division.

Ice floats on the water and a piece of wood usually does too. But why is that actually the case? This is exactly what we are dealing with in this article and we quickly end up with the Archimedes' principle. But first things first: If a body is completely or partially immersed in a liquid, it displaces the liquid and it appears as if this body is losing part of its weight. This is because the body experiences a force that counteracts the weight of the earth. This force is called the buoyancy force.

The amount of buoyancy caused by the liquid and the weight of the body are the same. And this is exactly what is understood by the Archimedean principle. In the following graphic you can see a body in a liquid. The weight force and the buoyancy force are shown.

Next, let's take a look at the formulas for calculating the buoyancy force and the weight force. The following relationships apply:


  • "F.G"the weight of the body in Newtons [N]
  • "F.A."the buoyancy force of the liquid / gas in Newtons [N]
  • "mbody"is the mass of the body in kilograms [kg]
  • liquid"the density of the liquid in kilograms per cubic meter [kg / m3 ]
  • body"the density of the body in kilograms per cubic meter [kg / m3 ]
  • "V" is the volume in cubic meters [m3 ]
  • "g" is the acceleration due to gravity in meters per square second [m / s2 ]

Rise, float, sink and swim

A number of different things can happen when a body is immersed in a liquid. The body can rise, float, sink and swim. And that's exactly what we're going to look at in detail:

  • Climb: If the buoyancy force acting on the body is greater than the weight, the body rises to the surface. The following applies: FA. > FG.
  • Hover: Buoyancy and weight are the same, but the body is completely submerged. The following applies: FA. = FG.
  • Sink: If the buoyancy force is less than the weight, the body sinks. The following applies: FA. G.
  • swim: A floating body is immersed in the liquid until the buoyancy force and weight are equal. The following applies: FA. = FG.


Who's Online

We have 1322 guests online