Home Back

How To Calculate The Speed Of Sound Formula

Speed of Sound Formula:

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

unitless
J/mol·K
K
kg/mol

Unit Converter ▲

Unit Converter ▼

From: To:

1. What is the Speed of Sound Formula?

The speed of sound formula calculates the speed at which sound waves propagate through a medium. For ideal gases, it is given by \( v = \sqrt{\frac{\gamma R T}{M}} \), where γ is the adiabatic index, R is the gas constant, T is the absolute temperature, and M is the molar mass of the gas.

2. How Does the Calculator Work?

The calculator uses the speed of sound formula:

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

Where:

Explanation: The formula shows that sound speed increases with temperature and decreases with molecular mass of the gas.

3. Importance of Speed of Sound Calculation

Details: Calculating sound speed is crucial for various applications including acoustics, meteorology, aerospace engineering, and medical ultrasound imaging.

4. Using the Calculator

Tips: Enter the adiabatic index (typically 1.4 for air), gas constant (8.314 J/mol·K), temperature in Kelvin, and molar mass in kg/mol. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical speed of sound in air at room temperature?
A: Approximately 343 m/s at 20°C (293 K) for dry air.

Q2: How does humidity affect sound speed?
A: Humidity slightly increases sound speed as water vapor has lower molar mass than dry air components.

Q3: Why is temperature in Kelvin used?
A: The formula requires absolute temperature because it's derived from kinetic theory where temperature is proportional to molecular kinetic energy.

Q4: What are typical γ values for common gases?
A: Air: 1.4, Helium: 1.66, Carbon dioxide: 1.3, Argon: 1.67

Q5: Does this formula work for liquids and solids?
A: No, this formula is specific to ideal gases. Sound speed in liquids and solids is calculated using different formulas involving bulk modulus and density.

How To Calculate The Speed Of Sound Formula© - All Rights Reserved 2025