The Law of Conservation of Energy is a fundamental principle of physics stating that energy cannot be created or destroyed, only transformed from one form to another or transferred between objects. The total energy of an isolated system remains constant over time.
For example, when a ball is dropped, its potential energy (due to height) is converted into kinetic energy (motion). When it hits the ground, some energy becomes sound and heat, but the total amount of energy remains the same—just in different forms.
This law applies universally, from mechanical systems to thermodynamics and even quantum physics. It’s the foundation for understanding energy flow in engines, ecosystems, electrical circuits, and the universe itself. Even in nuclear reactions, where mass is converted into energy (as per Einstein’s equation E=mc2E=mc^2), the total mass-energy remains conserved.
In essence, energy can change forms (like chemical to thermal) or move places, but it never vanishes or appears from nowhere.