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Speed Of Sound Formula

Speed of Sound Equation:

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

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J/mol·K
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kg/mol

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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 equation:

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

Where:

Explanation: The equation shows that sound speed increases with temperature and decreases with molecular mass of the gas. The adiabatic index represents how the gas responds to compression.

3. Importance of Speed of Sound Calculation

Details: Calculating sound speed is essential in various fields including acoustics, aerodynamics, meteorology, and engineering. It helps in designing audio systems, studying atmospheric conditions, and understanding gas properties.

4. Using the Calculator

Tips: Enter the adiabatic index (γ), gas constant (R), temperature in Kelvin (T), and molar mass (M). All values must be positive. The gas constant is typically 8.314 J/mol·K for ideal gases.

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. For air, it's approximately 1.4; for monatomic gases like helium, it's 1.67.

Q2: Why does temperature affect sound speed?
A: Higher temperature increases molecular motion, allowing sound waves to propagate faster through the medium.

Q3: How does molar mass affect sound speed?
A: Heavier molecules move more slowly, resulting in slower sound propagation. Lighter gases like helium have higher sound speeds.

Q4: Is this formula valid for all media?
A: No, this formula is specifically for ideal gases. Sound speed in liquids and solids is calculated using different formulas involving bulk modulus and density.

Q5: What is a typical speed of sound in air?
A: At 20°C (293K), sound travels at approximately 343 m/s in air with γ=1.4, R=8.314 J/mol·K, and M=0.029 kg/mol.

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