
#1
Sep108, 11:29 PM

P: 6

hi all, am a confusedbeing after trying to solve this really simple question..
somewhere somehow my concepts are just not right ): Consider an airplane flying with a velocity of 60m/s at a standard altitude of 3km. At a point on the wing, the airflow velocity is 70m/s. Calculate the pressure at this point. By using p1+1/2(rou)(v1)^2=p2+1/2(rou)(v2)^2 and the standard atmospheric pressure table, the given solution is 7.0121 X 10^4 + 1/2(9.0926X10^(1))(60^2)/2 = P2 + 9.0926X10^(1)(70^2)/2 I do not understand why P1 = 7.0121 x 10^4 N (given in the table), where P1 should be the pressure at the point of the flow where velocity is 60m/s. What is the pressure given in the table referred to as? I am confused with static/dynamic and total pressure! Would any kind soul please help? Thanks alot in advance! 



#2
Sep108, 11:53 PM

P: 4,780

http://en.wikipedia.org/wiki/Static_pressure
http://en.wikipedia.org/wiki/Dynamic_pressure P1 = 7.0121 x 10^4 N is the static (atmospheric) pressure at an altitude of 3km. 


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