Ambient air with a dew point of 18C and a relative humidity of 60% is conveyed at a rate of 1.5 m3/s through an electric heater. The air is heated to a dry bulb temperature of 50 C. The heated air is then allowed to pass through a tray drier that contains 200 kg of apple slices with an initial moisture content of 80% wet basis. The air exits the dryer with a dew-point temperature of 21.2 C. a. If the electrical energy costs 5 ¢/(kW h), calculate the electrical costs for heating the air per hour of operation. b. Calculate the amount of water removed by air from apple slices per hour of operation. c. If the dryer is operated for 2 h, what will be the final moisture content of the apple slices (wet basis)?