Problem $3(25$ points$)$: A static thrust stand with square cross section of $50$ cm sides intakes air of density $1\mathrm{.}25k\frac{g}{m^2}$ and discharges into the atmosphere as shown. Determine the mass flow rate needed to produce an anchoring force of $20$ kN in the $x-$direction. The intake pressure is uniform and $92\mathrm{.}3$ kPa below the atmospheric pressure. Consider the flow to be steady, incompressible and $2-$D$.$