$5-121$ A $2-m^3$ rigid tank initially contains air at $100$ kPa and $22C.$ The tank is connected to a supply line through a valve. Air is flowing in the supply line at $600$ kPa and $22C.$ The valve is opened, and air is allowed to enter the tank until the pressure in the tank reaches the line pressure, at which point the valve is closed. A thermometer placed in the tank indicates that the air temperature at the final state is $77C.$ Determine $($a$)$ the mass of air that has entered the tank and $(b)$ the amount of heat transfer.

Answers: $($a$)9\mathrm{.}58$ kg $,($b$)339$ kJ

FIGURE P$5-121$