Home Back

Speed Of Sound Calculation Formula

Speed of Sound Equation:

\[ v = \sqrt{\frac{\gamma R T}{M}} \]

unitless
J/mol·K
K
kg/mol

Unit Converter ▲

Unit Converter ▼

From: To:

1. What is the Speed of Sound Equation?

The speed of sound equation calculates the velocity at which sound waves propagate through a gas medium. It depends on the adiabatic index, gas constant, temperature, and molar mass of the gas.

2. How Does the Calculator Work?

The calculator uses the speed of sound equation:

\[ v = \sqrt{\frac{\gamma R T}{M}} \]

Where:

Explanation: The equation shows that sound travels faster in lighter gases, at higher temperatures, and in gases with higher adiabatic indices.

3. Importance of Speed of Sound Calculation

Details: Calculating the speed of sound is crucial in various fields including acoustics, aerodynamics, meteorology, and engineering design of sound-related systems.

4. Using the Calculator

Tips: Enter the adiabatic index (γ), gas constant (R), temperature in Kelvin (T), and molar mass in kg/mol (M). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the adiabatic index (γ)?
A: The adiabatic index is the ratio of specific heats (Cp/Cv) of a gas, which is approximately 1.4 for diatomic gases like air at room temperature.

Q2: Why is temperature in Kelvin?
A: The Kelvin scale is an absolute temperature scale required for thermodynamic equations where zero represents absolute zero.

Q3: How does molar mass affect sound speed?
A: Sound travels faster in gases with lower molar mass. Helium (low M) has higher sound speed than air, while sulfur hexafluoride (high M) has lower sound speed.

Q4: What is the speed of sound in air at room temperature?
A: Approximately 343 m/s at 20°C (293 K) with γ=1.4, R=8.314 J/mol·K, and M=0.029 kg/mol for air.

Q5: Does this equation work for liquids and solids?
A: No, this equation is specifically for ideal gases. Different equations are used for sound speed in liquids and solids.

Speed Of Sound Calculation Formula© - All Rights Reserved 2025