$3\mathrm{.}2\mathrm{.}8$ A shock wave is a very thin layer $($thickness $=l)$ 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. P$3\mathrm{.}2\mathrm{.}8.$ If $V_1=550\frac{m}{s},V_2=215\frac{m}{s},$ and $l=0\mathrm{.}0025mm,$ estimate the average deceleration of the gas as it flows across the shock wave. How many g$\text{'}$s deceleration does this represent?