Question

What is the net upward force on an airplane wing of area 21.0 m2 if the speed of air flow is 200 m/s across the top of the wing and 175 m/s across the bottom? (The density of air where the airplane flies is ?air = 1.21 kg/m3.

Answer 1

here,

From Bernoulli's theorem we have

Pa + 0.5 p va^2 = Pb + 0.5 p vb^2

Where Pa and Pb represent pressure

p represents density

va and vb represent velocity

Data:

Net force = ?

Area = A = 10.2 m.s^-2

Velocity across the top...= va = 200 ms^-1

Velocity across the bottom. ..=vb = 175 ms^-1

Density of air , p = 1.21 kgm^-3

Pa - Pb = 0.5 × 1.21× (200^2 - 175^2)

P = 5671.9 pascal

Since P= F/A

F = 270.1 newton

the net upward force on an airplane wing is 270.1 newton