An example of a machine that uses potential and kinetic energy is a pile driver. (A “pile” is another word for a big post, such as the piles which hold up a pier.) A pile driver is a machine with a huge mass on the end of a heavy metal cord. The huge mass is raised up high and then dropped. As the mass falls, it goes faster and faster and by the time it hits its target, it has enough energy to drive a huge post into the ground. The mass acquired that energy because as it was raised against gravity and the amount of gravitational potential energy increased. The potential energy was then changed into kinetic energy (energy of motion) when it was released. Any system wants to get to the lowest potential energy possible. A system is a group of parts or objects that work together, such as the parts of a mechanism or the parts of a large piece of machinery.
Another example of potential energy being changed to kinetic energy is an old pinball machine. If you are playing an old pinball machine where the ball is released by a spring, the ball sits on the spring (potential energy) until you let go of the button, the spring uncoils (changing the potential energy to kinetic energy), and the ball is put into play.
How energy is used?
What are 2 other examples of how potential and kinetic energy are used?
