1. The problem statement, all variables and given/known data A 1990 kg rocket is loaded with 102 kg of propellant. It exhausts the propellant in a burn of 25s. The rocket starts at rest, and moves with a speed of 240 m/s after the burn. Determine the impulse. 2. Relevant equations Impulse (p) = m1vf-m1vi 3. The attempt at a solution How would one calculate the impulse given that the mass changes because of the loaded propellant which is used up by the time the mass hits the final velocity.