What requires energy?

• A. Heat
• B. Motion
• C. Power
• D. Work

Answer: (D)

Energy must be used to perform work. Work is defined as the transfer of energy that occurs when a force moves an object through a distance, so carrying out work inherently involves consuming or converting energy. Heat, by contrast, is energy moving from one place to another because of a temperature difference rather than a deliberate use of energy to move something. Motion is a state—the object is moving—and while energy can cause motion, the action of moving itself isn’t the process that “requires energy” in the same active sense as doing work. Power describes how fast energy is being used or transferred, not a separate activity that requires energy in the way that performing work does.