Hydrodynamics (Law of Volume Flow)

Flow rate is the amount of time something takes to flow down a (funnel, of inclined plane) In physics and engineering, in particular fluid dynamics and hydrometry, the volumetric flow rate, (also known as volume flow rate, rate of fluid flow or volume velocity) is the volume of fluid which passes per unit time; usually represented by the symbol Q. The SI unit is m³/s (cubic meters per second). Another unit used is sccm (standard cubic centimeters per minute).

In US Customary Units and British Imperial Units, volumetric flow rate is often expressed as ft³/s (cubic feet per second) or gallons per minute (either U.S. or imperial definitions).

Volumetric flow rate should not be confused with volumetric flux, as defined by Darcy's law and represented by the symbol q, with units of m³/(m²·s), that is, m·s⁻¹. The integration of a flux over an area gives the volumetric flow rate.