Consider a rectangular wing mounted in a low$-$speed subsonic wind tunnel. The wing model

completely spans the test section so that the flow sees essentially an infinite wing. If the wing has an

NACA $23012$ aerofoil section and a chord of $0\mathrm{.}3$ m$,$ a$)$ calculate the lift, drag per unit span and the lift

to drag ratio when the airflow pressure, temperature, velocity and viscosity are l atm, $303$ K$,42$ m$/$s$,$

and $1\mathrm{.}82\backslash$times $105$ respectively. The angle of attack is $8\backslash$deg $.$ Cl$=0\mathrm{.}72$ Cd$=0\mathrm{.}42$

calculate the net skin$-$friction drag coefficient, the total skin$-$friction drag, and the total pressure drag

force on the wing