Explained Home Page 1. The amount of fuel that the rocket burns while accelerating the masses is determined as time of burn, since the fuel burns at a constant rate. The formula for time is given a few paragraphs below the rocket specifications. The time formula is derived from velocity.
Velocity is derived from simple calculus.
The rocket is arbitrarily given its basic characteristics. Then velocity is calculated from them. Since acceleration is velocity over time, it is denoted as v'. For any particular instant in time, acceleration is force over mass at that particular time. Velocity is the antiderivative of acceleration, which is a calculus determination.