Flow Measurement - Pitot Static Tubes Bernoulli's Equation etc.?

Ok, I have a question that needs answering and I have no Idea where to start:





A Pitot-static tube connected to water manometer is used to measure the velocity of air. If the deflection between the two arms of the manometer is 12.4cm, determine the air velocity when the density of air is 1.25kgm-3 and the density of the water in the manometer is 1000kg/m3.





Right, I would have thought to work out the velocity of air I would have to use the following equation:





C =


2 (Pstag - P)


√ ___________


ρ





I can't get that to come up clearly the equation should read the root of all of 2 (PStag-P) over roh





However I have not a clue how to transfer that information into the above format i.e. to work out the pressures with that data (either that or im going about it the wrong way altogether), if anyone knows how to solve the above question and show me how to do it I would be very grateful!

Flow Measurement - Pitot Static Tubes Bernoulli's Equation etc.?
The velocity pressure is the algebraic sum of the total pressure and the static pressure.
Reply:The formula you are looking for is derived from





Pressure= 1/2 rho (v squared) . Where rho is the air density and V is the true air speed.


The pressure found this way is the equivalent of Indicated Air Speed


This is the Pressure which Affects a body moving in the air.








You can work out the rest








To have an exact calculation you require to know g of the place where you are measuring