1. The problem statement, all variables and given/known data I'm working on a summer project dealing with high altitude balloons and I am trying to come up with a way to calculate the altitude at any given time, but I have not dealt with non uniform acceleration before. The formula I have for acceleration deals with both pressure and temperature, which changes in relation to altitude, but I can't seem to figure out how to calculate an altitude when my answer depends on a previous value of itself (new altitude from acceleration based on old altitude.) 2. Relevant equations This is all that I am really looking for right now. 3. The attempt at a solution I'm assuming that there is some kind of differential equation at work here, but I'm really just not seeing it right now.