Law that energy cannot be created or destroyed is called what?

Law that energy cannot be created or destroyed is called what?

• A. Law of Conservation of Energy
• B. Newton's Third Law
• C. Kinetic energy principle
• D. Gravitational law

Answer: (A)

Energy cannot be created or destroyed; it can only change from one form to another, and the total amount stays the same in a closed system. This idea is captured by the Law of Conservation of Energy. For example, a swinging pendulum constantly trades potential energy for kinetic energy as it moves, and back again; the energy you measure stays constant even though its form changes, with a tiny amount turning into heat due to friction. The other options describe different ideas: Newton's Third Law is about action-reaction forces, not about energy staying constant; a term like the kinetic energy principle isn’t a standard law describing energy flow; and a gravitational law explains how gravity works, not how energy is conserved.

Energy cannot be created or destroyed; it can only change from one form to another, and the total amount stays the same in a closed system. This idea is captured by the Law of Conservation of Energy. For example, a swinging pendulum constantly trades potential energy for kinetic energy as it moves, and back again; the energy you measure stays constant even though its form changes, with a tiny amount turning into heat due to friction. The other options describe different ideas: Newton's Third Law is about action-reaction forces, not about energy staying constant; a term like the kinetic energy principle isn’t a standard law describing energy flow; and a gravitational law explains how gravity works, not how energy is conserved.