Chapter 6, Problem 42P

Consider the curved duct of Prob. 6-41, except 4Ilow the cross-sectional area to vary along the duct $\left(A_1\ne A_2\right)$. (a) Write an expression for the horizontal force $F_x$ of the fluid on the walls of the duct in terms of the given variables. (b) Verify your expression by plugging in the following values: $\rho =998.2kg/m^3$ , $A_1=0.025{\text{m}}^2$ , $A_2=0.015{\text{m}}^2$ , ${\beta }_1=1.02$ , $V_1=20\text{m/s}$ , $P_{1,gage}=88.34\text{kPa}$ ,, and $P_{2,\text{gage}}=67.48\text{kPa}$ .