Air flows over the top surface of an aeroplane wing at 80 m/s and under the wing at 60 m/s. If the wing area is 4 m² and the density of air is 1.3 kg/m³, what is the dynamic lift on the wing?

7280 N
3640 N
14560 N
72800 N

Correct answer: 7280 N

Solution

Faster flow over the top gives lower pressure there; the pressure difference times the wing area is the upward dynamic lift, from Bernoulli's equation.

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