A heat exchanger is used to heat cold water at 15°C entering at a rate of 2 kg/s by hot air at 85°C entering at a rate of 3 kg/s. The heat exchanger is not insulated and is losing heat at a rate of 30 kJ/s. The specific heat capacities of air and water can be found in the lesson slides. If the exit temperature of hot air is 20°C, choose the correct exit temperature for the cold water: a. 28°C b. 35°C C. 38°C d. 41°C e. 80°C

A heat exchanger is used to heat cold water at 15°C entering at a rate of 2 kg/s by hot air at 85°C entering at a rate of 3 kg/s. The heat exchanger is not insulated and is losing heat at a rate of 30 kJ/s. The specific heat capacities of air and water can be found in the lesson slides. If the exit temperature of hot air is 20°C, choose the correct exit temperature for the cold water: a. 28°C b. 35°C C. 38°C d. 41°C e. 80°C