Equations
Speed of sound in an ideal gas
Waves · id sound_speed_ideal_gas
v = \sqrt{\frac{\gamma R T}{M}}
| Symbol | Quantity | Unit | Meaning | Usual range |
|---|---|---|---|---|
v | speed of sound | m/s | Speed of sound waves in the gas | 10 to 5000 |
gamma | adiabatic index | dimensionless | Ratio of the heat capacities at constant pressure and volume | 1 to 1.7 |
R | molar gas constant | J/(mol*K) | Universal gas constant | |
T | temperature | K | Absolute temperature of the gas | 1 to 5000 |
M | molar mass | kg/mol | Mass of one mole of the gas | 0.002 to 0.3 |
Assumptions
- Ideal gas
- Sound compressions are adiabatic
Valid when
- Sound wavelength far longer than the mean free path
Found by
Questions with these words retrieve this equation: speed of sound, sound, air, gas, how fast sound travels, sound speed, adiabatic, temperature.
Source
OpenStax University Physics Volume 1, Chapter 17 (reference; entry written by the project). License: MIT. Entry confidence: 0.98.