(b) A water drop with an initial diameter of 2.5 mm is suspended on a thin wire in a large volume of air. The air is at a temperature of 26.65 C and a total pressure of 1 atm. Moisture present in the air exerts a partial pressure of 0.01036 atm. The wet-bulb temperature of the water drop is 15.55 C and the vapour pressure of water is 0.01743 atm. The diffusivity of water vapour at its average temperature of 21.1 C has been estimated to be 0.2607 cm-/s. Estimate the time required for complete evaporation of the water drop. The effect of curvature on the vapour pressure of water and convective effect may be neglected