Question

The flow speeds of air on the lower and upper surfaces of the wing of an aeroplane are v and respectively.The density of air is p and surface area of wings is A.The dynamic lift on the wing is-

Answer 1

Let, $P_1$ be the pressure for the lower wing and $P_2$ be the pressure of upper wing.

$P_1+\frac{1}{2}\rho V_1^2=P_2+\frac{1}{2}\rho V_2^2$

$P_2-P_1=\frac{1}{2}\rho (V_1^2-V_2^2)$------- (1)

$V_2=\sqrt{2}V$

$P_2-P_1=\frac{1}{2}\rho (V^2-2V^2)=-\frac{1}{2}\rho V^2$