Air at 1 atm and 285 k enters a 2-m-long rectangular duct with cross section 75 mmx150 mm. the duct is maintained at a constant surface temperature of 400 k, and the air mass flow rate is 0.10 kg/s. determine the heat transfer rate from the duct to the air and the air outlet temperature.

An open feedwater heater operates at steady state with liquid entering at inlet 1 with t? = 40°c and pl = 1 .2 mpa. water vapor att2-200°c and p2 = 1.2 mpa enters at inlet 2. saturated liquid water exits with a pressure of pa 1.2 mpa. neglect heat transfer with the surroundings and all kinetic and potential energy effects, determine the mass flow rate of steam at inlet 2 if the mass flow rate of liquid water at inlet 1 is given as 2 kg/s.