The speed 'v' of a longitudinal wave in an ideal gas of pressure

The speed 'v' of a longitudinal wave in an ideal gas of pressure
| The speed 'v' of a longitudinal wave in an ideal gas of pressure 'P' and density 'ρ' is equal to __________.

A. √(P/ρ)

B. √(ρ/P)

C. (P/&rho;)<sup>2</sup>

D. (&rho;/P)<sup>2</sup>

Please scroll down to see the correct answer and solution guide.

Right Answer is: A

SOLUTION

CONCEPT:

Speed of a longitudinal wave in an ideal gas:

  • In a longitudinal wave, the particles of the medium oscillate forward and backward in the direction of propagation of the wave.
  • They cause compressions and rarefactions of small volume elements of the medium.
  • Speed of a sound wave in an ideal gas is given by:

\(v = \sqrt {\frac{{P}}{ρ }} \)

where P = Pressure of the gas and ρ = density.

EXPLANATION:

  • Speed of a sound wave in an ideal gas is given by:

\(v = \sqrt {\frac{{P}}{ρ }} \)

  • Therefore option 1 is correct.