Hi, im a tennis coach and not very sciency, so if theres a simple answer to this question rather than a crazy physics answer it would be much appreciated. I hit the ball, some of the energy from my racket "pushes" thru the ball creating momentum, another part of the energy from my racket "brushes" around the ball creating spin. Are there 2 different names for these kinds of force and what are they? So for instace rather than saying " put more spin on the ball. " i could say "increase the ......... " or something like that Thanks for the help.