The density of a sample of air is 1.157 kg/m3, and the bulk modulus is 1.42 · 105 N/m2.

a) Find the speed of sound in the air sample. -----> I found it 350.3 m/s and its correct.

b) Find the temperature of the air sample. Give answer in °C. ----> I cant find this :S

Can you help me, please?

1 answer

The bulk modulus K used here is the so-called adiabatic bulk modulus and this is related to the pressure P according to:

K = gamma P

where gamma = cp/cv = approximately 1.4 for air.

So, you know the pressure and the density and then you can find the temperature via the ideal gas law.