A finite wing of span b=10 m has circulation $\Gamma(y)=\Gamma_0\sqrt{1-(2y/b)^2}$, with Γ₀=20 m²/s. Free-stream density and speed are 1.2 kg/m³ and 100 m/s. Find total lift in kN (two decimal places).
Kutta–Joukowski gives lift per span ρUΓ. Integrating the elliptical distribution yields $\int_{-b/2}^{b/2}\Gamma\,dy=\Gamma_0\pi b/4$. Thus $L=1.2\times100\times20\times\pi\times10/4=18849.6$ N = 18.85 kN.
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