My basic question is this. Can usable energy be extracted from a mechanism that has force only, no movement. Here is an example. You press a hard cover book against a wall. You now lean into the book thus there is static force against the wall. There is no movement, just force. This happens over and over, you release the force and re-apply the force over and over, the book never moving to or from the wall. How can one extract the force and convert it into usable energy? I realize energy can not be created, only converted. How can the weight of my body exerting force to the wall via the book be extracted without movement?