For a certain gas, Cp = 840.4 J/kg-K; and Cv = 651.5 J/kg-K. How fast will sound travel in this gas if it is at an adiabatic state with a temperature of 377 K.

Respuesta :

Answer:

The speed of the sound for the adiabatic gas is 313 m/s

Explanation:

For adiabatic state gas, the speed of the sound c is calculated by the following expression:

[tex]c=\sqrt(\gamma*R*T)[/tex]

Where R is the gas's particular constant defined in terms of Cp and Cv:

[tex]R=Cp-Cv[/tex]

For particular values given:

[tex]R=840.4 \frac{J}{Kg-K}- 651.5 \frac{J}{Kg-K}[/tex]

[tex]R=188.9 \frac{J}{Kg-K}[/tex]

The gamma undimensional constant is also expressed as a function of Cv and Cp:

[tex]\gamma=Cp/Cv[/tex]

[tex]\gamma=840.4 \frac{J}{Kg-K} / 651.5 \frac{J}{Kg-K} [/tex]

[tex]\gamma=1.29 [/tex]

And the variable T is the temperature in Kelvin. Thus for the known temperature:

[tex]c=\sqrt(1.29*188.9 \frac{J}{Kg-K}*377 K)[/tex]

[tex]c=\sqrt(91867.73 \frac{J}{Kg})[/tex]

The Jules unit can expressing by:

[tex]J=N.m=\frac{Kg.m}{s^2}* m[/tex]

[tex]J=\frac{Kg.m^2}{s^2}[/tex]

Replacing the new units for the speed of the sound:

[tex]c=\sqrt(91867.73 \frac{Kg.m^2}{Kg.s^2})[/tex]

[tex]c=\sqrt(91867.73 \frac{m^2}{s^2})[/tex]

[tex]c=313 m/s[/tex]

Answer:

Sound will travel with a speed of 302.9 m/sec

Explanation:

We have given [tex]c_p=840.4j/kg-K[/tex]

And [tex]c_v=651.5j/kg-K[/tex]

Temperature T = 377 K

Gas constant [tex]R=c_p-c_v=840.4-651.5=188.9j/kg-K[/tex]

And [tex]\gamma =\frac{c_p}{c_v}=\frac{840.4}{651.5}=1.289[/tex]

Speed is given by [tex]v=\sqrt{\gamma RT}=\sqrt{1.289\times 188.9\times 377}=302.9794m/sec[/tex]

So sound will travel with a speed of 302.9 m/sec