Question

Write down the factors affecting velocity of sound in gases.

Answer 1

1. Effect of pressure:
   Speed of sound is independent of pressure for a fixed temperature.
2. Effect of temperature:
   Speed of sound varies directly to the square root of temperature in kelvin. Speed of sound in air increases by 0.61 ms^-1 per degree celcius rise in temperature.
3. Effect of density:
   Velocity of sound in a gas is inversely proportional to the square root of the density of the gas.
4. Effect of moisture (humidity):
   Speed of sound increases with rise in humidity.
5. Effect of wind:
   In the direction along the wind blowing, the speed of sound to wind blowing, the speed of sound decreases.