Okay what about some real world applications:

1. A cloud is cylindrical in shape with a cross-sectional area of 10 km²and a height of 3 km. All of the cloud is initially supercooled and the liquid water content is 2 g m^-3. If all of the water in the cloud is transferred on to ice nuclei present in a uniform concentration of 1 liter^-1 , determine the total number of ice crystals in the cloud and the mass of each ice crystal produced. If all the ice crystals precipitate and melt before they reach the ground what will be the total rainfall that is produced?

2. Calculate the radius and the mass of an ice crystal after it has grown by deposition from the vapor phase for half an hour in a water-saturated environment at -5 C. .Assume that the crystal is a thin circular disk with a constant thickness of 10 microns.