(a) estimate the number of water molecules are in the earth'satmosphere
(b) given that the mean residence time of a water molecule in theearth's atmosphere is 9 days, use the result of part (a) toestimate the flow rate of liquid water from the atmosphere to theearth's surface (units in m^3s^-1)
(c) if the flow that you determined in (b) occurred as rainfalluniformly over the earth's surface, what would be the mean annualrainfall (cm/y)?