1What is Potential Energy?
Think of potential energy as "energy at rest" or energy that is waiting to happen. Just like a battery stores power for your toys, objects can store energy based on their position or shape. For example, when you pull back the string on a bow or lift a heavy ball high into the air, you are packing it with potential energy! The higher an object is from the ground, the more potential energy it has because gravity is waiting to pull it down. Scientists call this "gravitational potential energy," and it is the reason why a roller coaster feels so powerful right before it drops over the first big hill.
2Kinetic Energy: Energy in Action
Once an object starts moving, that stored potential energy doesn't just vanish—it transforms into kinetic energy! Kinetic energy is the energy of motion. Anything that is zooming, rolling, or flying has kinetic energy. The amount of kinetic energy depends on two things: how much an object weighs and how fast it is going. A heavy truck driving at 60 miles per hour has much more kinetic energy than a small bicycle going the same speed! Whenever you see something in motion, from a spinning fan to a falling leaf, you are seeing kinetic energy in its most exciting form.
3The Great Energy Transformation
One of the most important rules in science is that energy cannot be created or destroyed; it can only change its "disguise." This is called the Law of Conservation of Energy. On a roller coaster, the ride is a constant trade-off between potential and kinetic forms. As you go up, potential energy increases. As you dive down, it turns into kinetic energy. However, some energy also turns into sound (the rattle of the tracks) and heat (the friction of the wheels). Even though a pendulum eventually stops swinging, the energy hasn't disappeared—it has simply spread out into the air as tiny, invisible amounts of heat!