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## Homework Statement

A wind tunnel is designed to draw in air from the atmosphere and produce a velocity of 100m/s in the test section. THe fan is located downstream of the test section. What pressure is to be expected in the test section if the atmospheric temperature and pressure are -20C, 90kPa?

## Homework Equations

Bernoulli's Equation: P

_{1}+ 1/2

*p*v

^{2}+

*p*gh

_{1}= P

_{2}+ 1/2

*p*v

^{2}+

*p*gh

_{2}

*p =*P/RT

## The Attempt at a Solution

I cancelled out the heights as it doesn't state a height difference and says the fan is downstream, so assumed its a two dimensional problem. Leaving me with:

P

_{1}+ 1/2

*p*v

^{2}= P

_{2}+ 1/2

*p*v

^{2}

Then I used

*p*= P/RT to find the density of air, which came out to be 1.24kg/m

^{3}

Then Isolated P

_{2}= P

_{1}- 1/2

*p*v

^{2}, using atmospheric pressure for P

_{1}, I solved for the pressure afterwards but it came out to be -560kPa.

Now i know taking the absolute value is acceptable with pressures but this number still seems wrong to me.