I'm not sure if this is the appropriate place, but I've just been searching, with no luck, on how to solve a spring system with RK4 (hence the math section, since it's a Runge Kutta question). How would you set it up to change position based on spring properties? I haven't really found any consistent things either, except that x' = v and v' = a (which is standard). What would one iteration look like? As far as having position and velocity as your inputs, and outputting an updated position after the iteration. I know how to do RK4, just not so great at implementing it.