c) Extra credit: The drag force from air resistance is given by F= pACv2/2. where p is the density of air, A is the cross-sectional area (assume to be a circle), C is the drag coefficient based on shape and v is the speed. You may guess that larger raindrops may have a larger terminal speed, but let's see if this is true. Assume a spherical raindrop of radius r and density p.. I) Derive an expression for the terminal speed of the raindrop in terms of r, C, g. pw and p. (where p, is the density of air that is in the drag force expression). Mass cannot be in your expression. il) From your expression, if you double the radius, what happens to the terminal speed