Which statement best describes the law of conservation of energy?

The law of conservation of energy states that energy in a closed system can neither be created nor destroyed; it can only be transformed from one form to another. This principle means that the total energy within the system remains constant, even as it changes from kinetic energy to potential energy or between other forms such as thermal, chemical, or electrical energy.

For instance, when a roller coaster goes down a hill, potential energy is converted into kinetic energy—the total energy remains the same, but its form changes. This concept is fundamental in various fields, such as physics, engineering, and chemistry, illustrating that energy transitions are a natural occurrence in both mechanical systems and other processes in nature.

Other statements do not accurately reflect the law of conservation of energy. For example, the idea that energy can be created does not align with this law, as it strictly emphasizes that energy is conserved. Additionally, while work does relate to energy changes, claiming that energy can simply increase by doing work doesn't encompass the full scope of conservation. Lastly, the notion that energy is only present in living organisms is incorrect, as energy exists in many forms across all matter, not limited to biological entities.