Question 50. In a wind tunnel test on a model aeroplane, the speed of air over the upper surface of the wing is 70 m/s. The speed of air over the lower surface of the wing is 65 m/s. The area of the wing is 2 m². Find the lift produced by the wing. Density of air is 1.2 kg m⁻³. The lift of the wing is ____ N.
Answer: 810
Explanation:
Lift on the wing is given by F=\frac{1}{2}\rho\left(v_{1}^{2}-v_{2}^{2}\right)A
Substitute the given values,
F=\frac{1}{2}\times1.2\times\left(70^{2}-65^{2}\right)\times2Simplifying, F=810 N