1. The problem statement, all variables and given/known data This is actually related to another https://www.physicsforums.com/showthread.php?t=531596" basically, I have a Constance force of gravity, and a non constant force of a rocket going the opposite way. the net force would be something like F(booster) -Force(gravity). Assumed (-) direction, and Force(booster) is smaller. I know when acceleration isn't constant we have to integrate the equation. 2. Relevant equations a = dx/dt 3. The attempt at a solution a=( F(booster)- F(gravity) )/m a=( F(booster)- mg) )/m but I'm not sure how i should go about integrating this mess.