Editing Displacement (fluid) (section)

{{Short description|Fluid displaced when an object is immersed in it}}

[[File:Displacement-measurement.svg|thumb|upright=1.3|Measurement of volume by displacement, (a) before and (b) after an object has been submerged. The amount by which the liquid rises in the cylinder (∆V) is equal to the volume of the object.]]

In [[fluid mechanics]], '''displacement''' occurs when an object is largely immersed in a [[fluid]], pushing it out of the way and taking its place. The volume of the fluid displaced can then be measured, and from this, the volume of the immersed object can be deduced: the volume of the immersed object will be exactly equal to the volume of the displaced fluid.

An object immersed in a liquid displaces an amount of fluid equal to the object's volume. Thus, [[buoyancy]] is expressed through [[Archimedes' principle]], which states that the [[weight]] of the object is reduced by its volume multiplied by the [[density]] of the fluid. If the weight of the object is less than this displaced quantity, the object floats; if more, it sinks. The amount of fluid displaced is directly related (via Archimedes' principle) to its volume. In the case of an object that sinks (is totally submerged), the volume of the object is displaced. In the case of an object that floats, the ''weight'' of fluid displaced will be equal to the weight of the displacing object.