In aircraft design, “density” is not used to describe the weight of an aircraft. Instead, the weight of an aircraft is typically measured in units like pounds (lb) or kilograms (kg), and it’s a force due to gravity acting on the mass of the aircraft.
- ρ = Density of the fluid (in kilograms per cubic meter, kg/m³)
- P = Pressure of the fluid (in pascals, Pa)
- R = Specific gas constant for the fluid (in J/(kg·K))
- T = Temperature of the fluid (in kelvin, K)