# Homework Help: Rain Drops falling down in a uniform cloud

1. Dec 20, 2009

### Erfan

1. The problem statement, all variables and given/known data
Consider a uniforms cloud of density ρ1 which consists of many little drops that are approximately still.Consider a special rain drop that is a little more bigger than the others so that it starts to fall down.Water drops stays spherical all the way.But the radius gets higher as it falls down.Also water's density is ρ0.
(a) Find a relation between $$\dot{r}$$, velocity of the drop, and the two densities.
(b) Find rain drop's acceleration.
2. Relevant equations

3. The attempt at a solution
The differential equation is non-linear.

2. Dec 20, 2009