Answer
$$69.81\;kg/s$$
Work Step by Step
By applying Bernoulli’s equation and the equation of continuity to points A and B, we can show that the fluid flows through the point A with speed
$v_B=\sqrt {\frac{2(p_B-p_A)A^2_A}{\rho(A^2_B-A^2_A)}}$
Therefore, the volume flow rate is given by
$R=A_Bv_A$
or, $R=A_B\sqrt {\frac{2(p_B-p_A)A^2_A}{\rho(A^2_B-A^2_A)}}$
or, $R=A_AA_B\sqrt {\frac{2(p_B-p_A)}{\rho(A^2_B-A^2_A)}}$
Therefore, the mass flow rate is
$R_m=\rho R$
or, $R_m=\rho A_AA_B\sqrt {\frac{2(p_B-p_A)}{\rho(A^2_B-A^2_A)}}$
Substituting the given values
$R_m=900\times1.90\times10^{-2}\times9.50\times10^{-2}\times\sqrt {\frac{2\times7.20\times10^3}{900\times\{(9.50\times10^{-2})^2-(1.90\times10^{-2})^2\}}}\;kg/s$
or, $\boxed{R_m=69.81\;kg/s}$
Therefore, the mass flow rate is $69.81\;kg/s$
