Steam is leaving a pressure cooker whose operating pressure is 20 psia. It is observed that the amount of liquid in the cooker has decreased by 0.6 gal in 45 minutes after the steady operating conditions are established, and the cross-sectional area of the exit opening is 0.15 in?. Determine (a) the mass flow rate and the exit velocity of the steam, (b) the total and flow energies of the steam per unit mass, and (c) the rate at which energy is leaving the cooker by steam. Sat. vapor P= 20 psia