Q $2)$ a$)$ Explain with a suitable sketch how a shock wave or system of shock waves can be used for the intake of an air$-$breathing engine for supersonic flight to decelerate the gas to subsonic speed. Calculate the stagnation pressure ratio and isentropic efficiency of a normal shock intake for flight Mach number $\backslash ($ M$=2\mathrm{.}0\backslash )($equations for the normal shock process are provided at the back of the script, and use $\backslash (\backslash$gamma$=1\mathrm{.}4\backslash )).$ Is the value for this flight Mach number acceptable?