Question

What is the formula for speed of sound in terms of pressure and density?

(a) a=\(\sqrt{\frac{\gamma P}{\rho}}\)

(b) a=\(\sqrt{\frac{\gamma\rho}{P}}\)

(c) a=\(\sqrt{\frac{\gamma RP}{\rho}}\)

(d) a=\(\sqrt{\frac{\gamma P}{\rho R}}\)

The question was asked during an online exam.

Enquiry is from Measurement of Airspeed topic in portion Atmosphere and Air Data Measurement of Aircraft Performance

Answer 1

Right answer is (a) a=\(\sqrt{\frac{\gamma P}{\rho}}\)

To elaborate: The formula for speed of sound in terms of pressure and density is given by a=\(\sqrt{\frac{\gamma P}{\rho}}\) where a=speed of sound, P=pressure, ρ=density and γ is the ratio of specific heat at constant pressure to that of specific heat at constant volume.