Story of Kinetic and Potential Energy

Once upon a time, a very small man had to do battle with a very large giant. The only thing that the small man had going for him was his sling. When got loose with it, the mass of the stone combined with its speed to give it kinetic energy, with which it was able to do work on the giant. Thereby applying force and exerting that force through a distance. The stone had energy thanks to its movement. Indeed, everything that moves has energy. Even the air around us. Once air is moving, it has the energy to drive windmills. Just as when water is moving, it has the energy to drive water mills. But if every moving thing has kinetic energy, does that mean that things which aren't moving don't have energy? In that case, why are you staring up at that rock searched on the edge of the clip? Why be frightened of it? It can't have any kinetic energy because it's not moving, and if it hasn't any kinetic energy, it can't do any work on you, can it. But maybe you'd better move out of the way all the same. Ah. Why? Because of The Rock's position on the edge of the cliff. It hasn't any movement so far, but it looks as if it's on the point of having quite a lot of movement any minute now. Because the force of gravity wants very much to make it fall off the cliff. That means that in a sense, The Rock has a lot of energy stored up in it. A lot of what scientists call potential energy. Or the energy of position, the slightest puff of wind, and that potential energy will immediately start being transformed into kinetic energy. And. That's how the energy of position becomes the energy of movement. Don't look now. But it's time to use some more kinetic energy to do some more work on that giant. Whoops. Hold on. What's happening? Let's do that again in slow motion. The stone last more and more speed as it left your sling because of the force of gravity trying to pull it down. The higher it got, the slower it went, and the less kinetic energy it had. Until at last it came to a complete stop and had no kinetic energy left in it at all. And therefore, no work in it, and no force that it could exert on the giant. But where did all that kinetic energy go? Is it lost forever? No. It's being transformed into potential energy. The work that the little man put into slinging the stone is now stored up in the stone. But of course, in reality, the stone only stops for a split second, and then immediately starts coming down again. Until it has got back, all the kinetic energy that it had in the first place. Meanwhile, back at the cliff edge, the giant finds all this very music. But he'd better watch out. Because most of the kinetic energy it took for him to climb up to the top of the clip is now stored in him by virtue of his position. These full of potential energy just waiting to be converted back into kinetic energy any minute now. Timur.