Question

A small jet airplane has a total wing area of 77.5 m2 and a mass of 7.23 104 kg. (a) If this jet is in horizontal flight, determine the pressure difference between the lower and upper surfaces of the wings.

Answer 1

To solve this problem we must simply resort to Newton's second law as well as the relationship between pressure and force as a physical unit applied in a given area.

In mathematical terms the Weight can be expressed as

$F_w = mg$

Where,

m = mass

g = Gravitational Acceleration

We have the mass and the gravitational acceleration therefore the Weight is

$m = 7.23*10^4Kg$

$g = 9.8m/s^2$

Replacing we have

$F_w = (7.23*10^4)(9.8)$

$F_w = 708540 N$

In this way the pressure exerted according to the active Area is,

$P = \frac{F}{A}$

$P = \frac{708540}{77.5}$

$P = 9142.45Pa$

Therefore the pressure difference between the lower and upper surface of the wings is 9.14kPa