So I was thinking physical a while back and I came up with some conceptual conundrums and I was hoping some fine folk can help me sort it out. So to change a particle's position, we must apply momentum. For this to be done we must apply a force. and for this, a yank and so on. My question is, how is that we can move the object if we must first change this infinite time derivative of momentum before anything else? and why is force the most important of these? i.e. why are there fundamental forces rather than fundamental yanks? Another problem: my brain is telling me that torque defies conservation of energy. If you spin an object with some force near its edge, move closer to the point of pivot and absorb the force from there aren't you getting more force than what you put in?