Moist air enters a duct at 10 oc, 70% relative humidity, and a volumetric flow rate of 150 m3/min. the mixture is heated as it flows in the duct and exits at 40oc. no moisture is added or removed, and the mixture pressure remains approximately constant at 1 bar. for steady-state operation, determine (a) the rate of heat transfer, in kj/min, and (b) the relative humidity at the exit. change in kinetic and potential energy can be ignored.