How would you go about determening a linear frequency, compared to that of a rotational frequency. For instance, determining the frequency of a piston in cylcles/second? I would assume velocity has to be involved, and the length of the stroke. How is velocity put into play, is it constant, or does it go in one direction, stop at 0 velocity, and then immediatly speed back up. Thats what it would do in the engine, but how do you account for this? Help please!