Q$2)$ Argon $($molecular mass $40)$ flows through a duct of area $15$ cm$^2.$ At a section the pressure and temperature of the gas are $1\mathrm{.}5*10^5$ N$/$m$^2$ and $310$ K$.$ If the velocity of the gas at this section is $55$ m$/$s$,$ calculate the mass flow rate. Argon $($molecular mass $40)$ flows through a duct of area $15$ cm$^2.$ At a section the pressure and temperature of the gas are $1\mathrm{.}5*10^5$ N$/$m$^2$ and $310$ K$.$ If the velocity of the gas at this section is $55$ m$/$s$,$ calculate the mass flow rate.