Question 4 This question has two separate parts. Solve both of them. (a) An aircraft with a wing span of b = 15m is flying at a speed of V. = 60m/s. The wing can be considered thin. The wing has an elliptic shape which can be described by i. ii. c(y) = Co 1 c 4y b Demonstrate that the average chord length Caug Co/4 (Hint: Ja sin0d0=[0-sinecose]|) Calculate the surface area of the wing. IT r = bro = [4 marks] [2 marks] iii. The spanwise circulation is also elliptic and after integration along the span the total circulation is known to be Also, the downwash and lift coefficient are known to be w = -[o/2b and CL = 1.2, respectively. Derive an expression for I of the following form : To A Co. Determine constant A. = [4 marks]