This is something I can't get my head around, and hopefully someone here could help. Say you have a fixed permanent magnet (not an electromagnet), and you place a metallic object with mass nearby. The object will begin to accelerate toward the magnet due to magnetic force. At the moment before impact with the magnet, the object has an instantaneous velocity greater than zero, meaning that it has kinetic energy. Where does that energy come from? I know magnets don't "deplete" the more they are used, so would that mean that a magnet has infinite potential energy?