Air at 1 atm flows at 2 m/s across the surface of a 2 inch long surface that is covered with a thin film of water. if the air and water are at 25°c and the diffusivity of water in air is 0.25 cm²/s, estimate the water mass flux for the evaporation of water at the middle of the surface, assuming laminar boundary-layer flow. is this assumption reasonable? from perry’s handbook, for air at 25°c, μ = 0.018 cp at 25°c, the vapour pressure of water is 0.46 psia. make sure to answer if the assumption is reasonable