Air flows steadily through the variable area pipe shown in the figure below. Determine the flow rate if viscous and compressibility effects are negligible.

Hint:

Apply hydrostatics to determine p$1$ and p$2,$ hence $($p$1-$p$2).$ Note that you may neglect the density of air compared to the density of water.

Apply Bernoulli's equation between points $1$ and $2$ to determine $v1.$ Note that $z1=z2$ and $v2=0.$

Find the volumetric flowrate $Q=A1*v1$