Mass flow rates can be calculated by determining temperature and what else?

The calculation of mass flow rates is often based on the relationship between the flow of a substance and its physical properties. In this context, temperature and pressure are two critical variables. Pressure is essential because it affects the density of a fluid, and thus influences the amount of mass that is flowing through a given cross-sectional area per unit of time.

When measuring liquid or gas flows, pressure impacts how tightly packed the molecules are, which directly correlates to density. For example, at higher pressures, gases will generally have a higher density compared to lower pressures. Given that mass flow rate is defined as the mass of a substance passing a given point per unit time, both temperature and pressure are necessary to accurately determine how dense the material is, which then allows for the calculation of the mass flow rate.

Temperature, in this equation, helps to define the state of the fluid, while pressure complements that by adjusting the density. Therefore, knowing both temperature and pressure provides a complete picture to accurately calculate mass flow rates.