Question

Problem: The altimeter of a low-speed Piper Aztec reads 8000ft. A Pitot tube mounted on the wingtip measures a pressure of 1650 lb/ft2 . If the outside air temperature is 500 deg R, What is the true velocity of the airplane?, What is the equivalent airspeed?

How did they get the pressure of 2.34e-3 for airspeed in step 4?

(4 Bookmarks) Show all steps: ON Chapter 4, Problem 21P = 1.83x10 E Comment Step 3 of 4 A Calculate the pressure measured ythe pilot tube by using the following equation; PP+pv Here Pis pressure measured by the pilot tube, pis static pressure, pis density and is speed of the flow Rearrange the equation for as follows; 2(P-P) slug for P lb for P 1,83x10 Slug for P Substitute 1572 e 1650 e lh 1650 slug 1572 183x103 slug ft = 292.0 s Hence, actual speed of the plane is 292.0 Comment Step 4 of 4 A Calculate the equivalent air speed by using the following equation: 2(P-P) p. Substitute 1572 for P 1650for P2.34 x 10 for p, in the equation. ft ft 1572 slug ft Ib 1650 ft 2.34x10 slug = 256,0 Hence, the equivalent airspeed is 256.0 Comments (1) Anonymous Where did you get the value for roe(s) when finding equivalent air speed? Submit

Answer 1

Don't get confused.

2.34*10^-3 slug/ft³ is the value for ρ_s and not for the pressure for airspeed.

The values of pressures are-

P = 1572 slug/ft²

P_o= 1650 lb/ft²