A shock wave is a very thin layer (thickness \(=\ell\) ) in a highspeed (supersonic) gas flow across which the flow properties (velocity, density, pressure, etc.) change from state (1) to state (2) as shown in Fig. P4.30. If \(V_{1}=1800 \mathrm{fps}, V_{2}=700 \mathrm{fps}\), and \(\ell=10^{-4} \mathrm{in}\), estimate the average deceleration of the gas as it flows across the shock wave. How many \(g\) 's deceleration does this represent?

Figure P4.30

V V V V www Shock wave x V2