1. The problem statement, all variables and given/known data given a graph of the thrust of an engine, we need to determine what mass to make our rocket so that it goes 15m into the air. Here is the graph: http://www.321rockets.com/content/image/26402/800/A8_thrustcurve.jpg I just need some confirmation on if I'm doing it right. 2. Relevant equations Fnet= Ft+Fg=ma 3. The attempt at a solution Using the section of 0.0s-0.1s for refernce: - Find the average thrust force during this time interval (my teacher talked about how later we would use impulse for this, but we haven't learned that yet, so I calculated average force using the inital force for that interval (0N) and the final force for that interval (5N). Add together and divide by two, giving me 2.5N. This means during the first 0.1s of the rocket's flight, the average thrust force acting upon it is 2.5N. -I add this with the force of gravity to determine the net force. Net force also equals ma, so i divide that number my the mass for the acceleration value. - Using the initial velocity (0 for this segment), the time (0.1s) and the acceleration, i use the big 5 kinematic equations to find the displacement and the final velocity. This final velocity is the initial velocity of the next segment. The displacement is D1. - Keep finding D2,D3,..etc and add them all together, hopefully giving me a TOTAL distance of 15m. But I know that the last displacement (rocket going up but the engine is no longer thrusting) will only have a net force of mg, so i take that into consideration when calculating. good?