Question

Suppose a compressible gas is flowing through a pipe. In a region of the pipe with a cross-sectional area of 0.25 m^2, it has a flow rate of 6 m/s and a density of 2.5 kg/m^3. What is its density as it flows through another region of the same pipe with a cross- sectional area of 0.50 m^2 at velocity 3 m/s?

Answer 1

$$\rho_1 A_1 v_1=\rho_2 A_2 v_2\\(2.5)(0.25)(6)=(3)(0.5)\rho_2\\\rho_2=2.5\frac{kg}{m^3}$$