3.3 Conservation of energy

• Conserved: In physics, the term "conserved" refers to a quantity or property that remains unchanged over time within a specified system. This means that the total amount of the conserved quantity remains constant, even though it may change forms or redistribute within the system.
• Created: In the context of physics, "created" refers to the generation or production of something new within a system. This could involve the introduction of a new substance, energy, or other entities into the system, resulting in an increase in the system's overall content.
• Destroyed: In physics, "destroyed" typically implies the removal or annihilation of something within a system, resulting in a reduction or elimination of its presence. This could involve the conversion of a substance into other forms, the loss of energy, or the removal of particles or entities from the system.
• System: In physics, a "system" refers to a defined portion of the universe that is under consideration or study. It can be any collection of objects, particles, or fields that are chosen for analysis based on their interactions or relevance to a particular problem or question. The boundaries of a system may be arbitrarily defined, and it can encompass various components and phenomena.
• Energy Diagram: An energy diagram visually represents the flow and transformation of energy within a system. It illustrates how energy is converted from one form to another, such as electrical energy being transformed into light and thermal energy in an electric lamp or a car engine.
• The energy stored in a spring increases when the spring stretches (or compresses) because work has been done by external forces acting on the spring.
• Destroyed: In terms of energy conservation, "destroyed" implies the loss or dissipation of energy within a system. Despite this terminology, energy cannot truly be destroyed within a closed system; it merely changes form or is transferred out of the system.
• Conserved: Energy remains constant throughout a process if no energy is created or destroyed during the process.
• The law of conservation of energy states that energy cannot be created

  or destroyed, only changed from one form to another.
• In a closed system, energy is conserved.