1. The problem statement, all variables and given/known data Assume that a typical raindrop is spherical. Starting at some time, which we designate as t = 0, the raindrop of radius r sub o falls from rest from a cloud and begins to evaporate. a) If it is assumed that a raindrop evaporates in such a manner that its shape remains spherical, then it also makes sense to assume that the rate at which the raindrop evaporates - that is, the rate at which it loses mass - is proportional to its surface area. Show that this latter assumption implies that the rate at which the radius r of the raindrop decreases is a constant. Find r(t). There is a b part but I think I understand how that is done. 2. Relevant equations Surface Area of a Sphere is 4*pi*r2 3. The attempt at a solution -d(m)/dt is proportional to 4*pi*r2 Therefore dm/dt = -k*4*pi*r2 Where k is a constant to remove the proportionality. if dr/dt = constant represented by c then after we integrate that equation we get r(t) = c1*t + c2 After that I did some really weird math that I don't think is possible. Any ideas?