I am trying to figure out what I am doing. Forgive me, I’m not very sharp when it comes to differential equations… or even a useful working knowledge of calculus. I understand the concepts but if I can’t figure out how to type it into my TI-89 or get Wolfram alpha to do it… I’m kind of stuck and would appreciate some assistance. So to start: I have a system that has a combined momentum of 11.38 kg -meters/second. At least that is what I am estimating it to be. I know the mass of the moving part, and I know how fast it is going at it's peak. I built a test rig to hold the system, which contains a small explosive force, setting the system into motion. The system is butted against a load cell. After firing the peak force the load cell registered was 300 newtons. How do I get from momentum… to 300 newton’s force? I’m guessing it has to do with the spring rate of the load cell… which is very high. I believe the load cell only moves .127mm in its entire stroke and is good for. (http://www.transducertechniques.com/lpo-load-cell.aspx ... its LPO-5K) I keep thinking it’s somewhere in the relationship 1/2 m*v^2=1/2 k*x^2… but I’m pretty sure that somehow I have to figure out how long it takes the spring of the load cell to de-accelerate the mass, thus producing a force… I just don’t know how to do that/express that mathematically. -my first post... this seems like where I would put this question, forgive me if it belongs somewhere else.