Consider a streamline with the properties \(M_{1}=4.0\) and \(p_{1}=1 \mathrm{~atm}\). Consider also the following two different shock structures encountered by such a streamline: (a) a single normal shock wave and \((b)\) an oblique shock with \(\beta=40^{\circ}\), followed by a normal shock. Calculate and compare the total pressure behind the shock structure of each \((a)\) and \((b)\) above. From this comparison, can you deduce a general principle concerning the efficiency of a single normal shock in relation to an oblique shock plus normal shock in decelerating a supersonic flow to subsonic speeds (which, for example, is the purpose of an inlet of a conventional jet engine)?