Hi! I have apparently forgotten way too much college physics, and could really use some help here. I'm trying to calculate the impact force of an instrument (a Schmidt hammer--uses a spring-loaded piston) that produces an impulse against a surface. The instrument registers a rebound value (which I believe is a measure of rebound energy), and I know the impact energy. I don't have the impulse contact time, or the stopping distance, but both are very small (think very stiff spring-loaded metal piston slamming into a cement wall). So the question is, given only a change in energy (I don't think it matters if you think of it as spring potential, or kinetic just before impact) during an inelastic collision--plus any other information I may be overlooking that can be gleaned from the "rebound" (momentum?)--is there any way to calculate the impact force? Thanks in advance for your help!!