Mass flow rate

Mass of a substance which passes per unit of time

In physics and engineering, mass flow rate is the rate at which mass of a fluid passes through a surface over time. Its unit is kilogram per second (kg/s) in SI units, and slug per second or pound per second in US customary units. The common symbol is m ˙ {\displaystyle {\dot {m}}} (pronounced "m-dot"), although sometimes μ {\displaystyle \mu } (Greek lowercase mu) is used.

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