$1.$ For the sample airfoil data given previously on page $13$ of this presentation, find the lift, drag, and moment per unit length, if the chord is $6$ ft $.,$ the incoming flow is at std$.$ sea level conditions and $\backslash (100\backslash$mathrm$\{$ft$\}/\backslash$mathrm$\{$s$\}\backslash ),$ and the AOA is $5$ deg $.$

$2.$ In terms of lift to drag ratio, what is the best lift coefficient and angle of attack to operate this airfoil at$?$ What is the best L$/$D$?$

$3.$ What is the stall speed at sea level of an airplane that weights $\backslash (10,000\backslash$mathrm$\{$lbs$\}\backslash ).,$ has a wing area of $300$ sq$.$ft$.,$ and a maximum lift coefficient of $1\mathrm{.}4?$ What is the stall speed if flaps that double CLmax are applied?

$4.$ An airplane is flying at $108$ mph at sea level. It weighs $\backslash (2,000\backslash$mathrm$\{$lbs$\}\backslash ),$ has a wing span of $30$ ft $.,$ and a wing area of $\backslash (160\backslash$mathrm$\{$sq$\}.\backslash$mathrm$\{$ft$\}\backslash ).$ If$,$ the Oswald's efficiency is $0\mathrm{.}75,$ what is the induced drag in pounds