1. The problem statement, all variables and given/known data The mass of a rocket as it burns its fuel is constantly decreasing, while its speed is increasing. We want to know when the momentum is at its maximum. At what fraction of the initial mass is the momentum a maximum? 2. Relevant equations P = mv 3. The attempt at a solution I'm guessing I have to relate velocity to mass somehow so I can get an equation of momentum that is dependent on mass. Then I find when dP/dm = 0.