Thermofluids Question wind tunnel u tube manometer

[P111ltl]

Homework Statement

Air at 20 degrees celsius and 100kpa is drawn into a wind tunnel. If the deflection h of a water manometer that is connected to a hole in the wall of the test section to measure the gauge pressure in the flow is 98mm. Calculate air speed in test section in m/s ignore fluid friction .
Take R of air to be 287 j/kgK and density of water to be 1000 kg/m3 and g= 9.81

part b) if the air speed is 45 m/s calculate the deflection h in the manometer.

Homework Equations

I have been having trouble with this for ages now and am really stuck have been looking at Pressure= density xg x height giving 961.38 Pa then using pv=nrt v=87.469 using this method unsure if I am barking up the wrong tree?

for part b) again using p=nRT/v = 1868.68 Pa then using P=densityxgxdelta h giving 190mm or 0.19m however this doesn't sound right to me as the 45 m/s air speed is causing a greater deflection that the previously worked out air speed so i am sure something is not quite right but what? I am converting 20 degrees to 293 K and using that any suggestion?


If anyone needs a drawing i will attempt one in paint.

Thanks very much in advance

 

[member 553083]

for any help The Attempt at a SolutionI have been having trouble with this for ages now and am really stuck have been looking at Pressure= density xg x height giving 961.38 Pa then using pv=nrt v=87.469 using this method unsure if I am barking up the wrong tree?for part b) again using p=nRT/v = 1868.68 Pa then using P=densityxgxdelta h giving 190mm or 0.19m however this doesn't sound right to me as the 45 m/s air speed is causing a greater deflection that the previously worked out air speed so i am sure something is not quite right but what? I am converting 20 degrees to 293 K and using that any suggestion?