I was wondering how I could find out the thrust, any any other interesting facts about my model rocket motor, but maily the inpulse/thrust. Here is what I know/can measure: -mass of propelant and whole motor assembly -type of propelant (aswell as full expected reaction of propelant as it burns) -size of rocket motor, diameter, volume, nozzle diameter -theoretical total energy output/heat of the reaction of rocket -burn time As of right now, I dont think this particular rocket will move anywhere on its own power, so I cant really measure its distance moved (horizontal or vertical), or its velocity. from this information here, what can I find? (probably not much) What could I do to imporve so that I have more valuable info so as to find the thrust? Here is my idea for finding the thrust force the rocket exerts, hand the rocket from a string with the nozzle pointing down, have the other end of the string tied to a [spring] scale. Light the rocket and then throughout the time that it is burning, measure its appearant weight on the scale and then its final weight. You know the initial weight and time it took to burn, and then you can just assume it burns evenly the whole time. From that you can then find that at 'such and such' second it wieghed this amount, even though it really had a mass of 'whatever' (excuse the technical terms), and then you can calculate the thrust upward from that. This methold should work, in theory, since the rocket isnt strong enough to 'fly' upward under its own power, and if you like, it wouldnt have to be a sping scale, it could be a normal scale and then face the nozzle upward, in this way, even if the rocket could 'fly' it would still work. How does that sound, or is there a better way?