Which statement correctly describes potential energy and kinetic energy?

• A. Potential energy is energy of motion; kinetic energy is stored energy.
• B. Potential energy is energy produced by heat; kinetic energy is electrical energy.
• C. Potential energy is stored energy; kinetic energy is the energy of motion.
• D. Potential energy is energy only in liquids; kinetic energy is energy only in solids.

Answer: (C)

The core idea is that energy comes in two familiar mechanical forms: potential energy, which is stored energy due to position or configuration, and kinetic energy, the energy of motion. Potential energy depends on where something is or how it’s stretched or compressed—for example, a ball held at height has gravitational potential energy, a stretched spring has elastic potential energy, and chemical bonds hold chemical potential energy. Kinetic energy depends on how fast something is moving, and it increases with both mass and speed, described by KE = 1/2 m v^2.

The statement that matches these definitions says potential energy is stored energy and kinetic energy is the energy of motion. It reflects how energy can transfer between forms, such as a falling object converting gravitational potential energy into kinetic energy while the total mechanical energy remains the same in an ideal system.

The other ideas mix up these concepts or assign energy to conditions that aren’t accurate here—for instance, energy of motion is not stored energy, potential energy isn’t defined as energy produced by heat, and energy isn't limited to liquids or solids.