A light plane $($weight $10$ kN $)$ has a wingspan of $10$ m and a chord length of $1\mathrm{.}5$ m $.$ If the lift characteristics of the wing are like those given in Figure Q$1,$ what must be the angle of attack for a takeoff speed of $140k\frac{m}{h}?$ Calculate the stall speed? Assume two passengers at $800$ N each and standard atmospheric conditions. Explain why the stall speed of a plane is typically lower than the takeoff speed.

$(15$ markah$/$marks$)$

Coefficients of lift and drag for three wings with aspect ratios of $3,5,$ and $7.$

Rajah S$1/$Figure Q$1$