Required information A 0.13-mm-diameter dust particle whose density is 2.1 g/cm3 is observed to be suspended in the air at 1 atm and 25°C at a fixed point. Assume Stokes law to be applicable. The density of dust is given to be ps = 2.1 g/cm3 - 2100 kg/m2. The density and dynamic viscosity of air at 1 atm and 25°C are pp=1184 kg/m3 and p = 1.849-10-5 kg/m.s. Determine the updraft velocity of air motion at that location The updraft velocity of air motion is m/s.