An Archimedes number, named after the ancient Greek scientist Archimedes, to determine the motion of fluids due to density differences, is a dimensionless number in the form Archimedes (Greek: ΑΡΧΙΜΗΔΗΣ, Arkhimêas) ((287 BCE – 212 BCE) was a Greek mathematician, astronomer, philosopher, physicist and engineer born in the Greek seaport colony of Syracuse. ... Archimedes (Greek: ΑΡΧΙΜΗΔΗΣ, Arkhimêas) ((287 BCE – 212 BCE) was a Greek mathematician, astronomer, philosopher, physicist and engineer born in the Greek seaport colony of Syracuse. ... A subset of the phases of matter, fluids include liquids, gases, plasmas and, to some extent, plastic solids. ... Density (symbol: ρ - Greek: rho) is a measure of mass per unit of volume. ... In dimensional analysis, a dimensionless number (or more precisely, a number with the dimensions of 1) is a pure number without any physical units; it does not change if one alters ones system of units of measurement, for example from English units to metric units. ...

where:

• g = gravitational acceleration (9.81 m/s²),
• ρ_l = density of the fluid,
• ρ = density of the body,
• μ = fluid absolute viscosity.

Gravity is the force of attraction between massive particles due to their mass. ... Acceleration is the time rate of change of velocity, and at any point on a v-t graph, it is given by the gradient of the tangent to that point In physics, acceleration (symbol: a) is defined as the rate of change (or time derivative) of velocity. ... The metre, symbol: m, is the basic unit of distance (or of length, in the parlance of the physical sciences) in the International System of Units. ... The second (symbol s) is a unit for time, and one of seven SI base units. ... The Pitch Drop Experiment at the University of Queensland. ...

See also

• Fluid dynamics
• pi (also know as Archimedes constant)