Two drops of water, of diameter D1 = 1 mm and D2 = 2 mm, initially (at t=0) at 25 o C are allowed to fall in air of -20 o C. Assuming the lumped capacitance method valid and freezing to begin when the water reaches 0 o C, which drop will begin to freeze first? How far will it have fallen? It is safe to assume that the drops reach their respective terminal fall velocities instantaneously