Halliday, Resnick & Walker — Fluids: Problem 7

7 Fresh water flows horizontally from pipe section 1 of cross-sectional area $A_1$ into pipe section 2 of cross-sectional area $A_2$. Figure 14-25 gives a plot of the pressure difference $p_2 - p_1$ versus the inverse area squared $A_1^{-2}$ that would be expected for a volume flow rate of a certain value if the water flow were laminar under all circumstances. The scale on the vertical axis is set by $\Delta p_s = 600 \text{ kN/m}^2$. For the conditions of the figure, what are the values of (a) $A_2$ and (b) the volume flow rate?