12.48 Moist air enters a device operating at steady state at 1 atm with a dry-bulb temperature of 55°C and a wet-bulb temperature of 25°C. Liquid water at 20°C is sprayed into the air stream, bringing it to 40°C, 1 atm at the exit. Determine a. the relative humidities at the inlet and exit. b. the rate that liquid water is sprayed into the air stream, in kg per kg of dry air.