Consider the drainage of a toluene film trapped between a water drop and toluenewater interface. The radius of the drop is 1.5 mm. Calculate the time required for the film to drain from an initial thickness of 1 m to 50 nm. Given: water = 1000 kg/m3 , toulene = 870 kg/m3 , = 0.6 mPa.s, d = 1 mPa s and = 36 mN/m.