I'm struggling to get my mind around this concept: If you have a spring with a known spring constant, and you put a specific mass on it, compress it a certain distance and then release it, can you predict the distance it will travel with the information supplied? Or in other words, can I calculate where my slingshot will land if I know the spring constant? Second question: If I have all the information, can I scale the slingshot up or down, changing the spring and weight to get the same trajectory? And is the spring constant a linear equation? Thanks!