The energy associated with the motion and position of everyday objects.

• A. Kinetic energy
• B. Potential energy
• C. Thermal energy
• D. Mechanical energy

Answer: (D)

Mechanical energy is the energy tied to both how an object is moving and where it is located. It combines kinetic energy, the energy of motion, with potential energy, the energy stored because of position (like height or stretched springs). For everyday objects, you can see it in a roller coaster car at the top of a hill (mostly potential energy, ready to become motion) and as it speeds down (kinetic energy increasing while potential energy decreases). The total mechanical energy is the sum of these two forms.

Kinetic energy alone describes motion but not where the object is; potential energy alone describes position but not how fast it’s moving. Thermal energy is related to temperature and microscopic motion, not to the overall motion or height of a macroscopic object. That’s why the single term that covers both motion and position is mechanical energy.