a$.)$ Define stagnation enthalpy and stagnation temperature, do these quantities define stagnation state. Argon is stored in a reservoir at $300$ K$,$ determine stagnation enthalpy and velocity of sound in it$.\backslash$gamma $=1\mathrm{.}658$ and the molecular weight of argon is $39\mathrm{.}94.$

b$.)$ Compare the final values of the pressure in a duct generated by sudden closure of the exit valve with

i$.$ Hydrogen, $\backslash$gamma $=1\mathrm{.}4,$ R $=4125$ J$/$kgK

ii$.$ Air $\backslash$gamma $=1\mathrm{.}4,$ R $=287$ J$/$kgK

iii. Freon $\backslash$gamma $=1\mathrm{.}2,$ R $=135$ J$/$kgK

The initial flow conditions in each case are pressure $10$ bar, temperature $400$K and velocity $100$ m$/$s