Dry air passes over a flat plate, at the surface of which the water vapor concentration is 0.01 kmol/m3. The plate’s length is 5m (in the direction of airflow) and its width is 1m, and the free-stream velocity of the air is 2 m/s. If both the convecting air and the flat plate are at 300 K, find the total mass flow, NA (in kmol/s) of water vapor from the surface of the plate.