11. Task D: D1: D2: D3: D4: Why the sectional lift coefficient C, is zero at the wing tip? Why the sectional lift coefficient C₁ is almost "flat" near the mid-section

of the wing? What is the cause of C, distribution? Do you think the C₂ distribution is elliptical? If not suggest ways to make it elliptical. Use a few data point to verify the induced drag formula. (20 marks)