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## Homework Statement

air flows in a 4" pipe. at point A a 2[bar] pressure was measured and the temperature was 22°C. the velocity V

_{1}was 5[m/sec].

At point B, down the stream, a 1.2[bar] pressure was measured and the temperature was 32°C.

What is the velocity V

_{2}at point B.

## Homework Equations

The continuity equation:

[itex]\gamma[/itex]

_{1}A

_{1}V

_{1}=[itex]\gamma[/itex]

_{2}A

_{2}V

_{2}

Where [itex]\gamma[/itex]=specific gravity, A=section area.

The gas law:

pv=RT

Where: p=absolute pressure

[itex]v=\frac{1}{\rho}[/itex], [itex]\rho[/itex]=specific mass

## The Attempt at a Solution

The specific gravity at point A:

[tex]\gamma_1=10\frac{2E5}{287\cdot 295}=23.6[N/m^3][/tex]

The specific gravity at point B:

[tex]\gamma_2=10\frac{1.2E5}{287\cdot 305}=13.7[N/m^3][/tex]

The continuity equation, without the area, since it's the same on both points:

[tex]23.6\cdot 5=13.7\cdot V_2 \Rightarrow V_2=8.6[/tex]

The answer should be 7.05.