Pressure is a fundamental concept in physics and fluid mechanics that describes the force exerted per unit area on a surface. It quantifies the intensity of the distributed force that a fluid (liquid or gas) exerts on its surroundings due to molecular interactions and collisions. Pressure is a scalar quantity and is typically measured in pascals (Pa), where 1 pascal is equal to 1 newton per square meter.
- : Pressure of the fluid (in pascals, Pa).
- : A constant that depends on the specific fluid and units (in pascals raised to the power of ).
- : Density of the fluid (in kilograms per cubic meter, kg/m³).
- : Specific heat ratio (dimensionless), which is the ratio of specific heat capacities at constant pressure () and constant volume () for the fluid.