What is the principle that states that energy cannot be created or destroyed?

The principle stating that energy cannot be created or destroyed is known as the law of conservation of energy. This fundamental concept in physics asserts that within a closed system, the total amount of energy remains constant over time. Energy can only change from one form to another, such as from kinetic energy to potential energy, or be transferred from one object to another, but the overall energy quantity is unchanged.

This principle is foundational to numerous scientific disciplines, including physics and chemistry, as it underpins concepts such as mechanical systems, thermodynamics, and even biological processes. The law of conservation of energy is crucial for solving problems involving energy exchanges and transformations, making it a key concept for students studying physical science.

Other concepts, such as Newton's first law, generally pertain to motion and inertia, while thermodynamics encompasses broader principles governing heat and energy transformations, but do not specifically define the idea of energy conservation itself. The principle of energy transfer, while related to how energy moves between systems, does not accurately capture the essence of energy conservation as stated in the law.