Which term means the ability to do work?

• A. Energy
• B. Power
• C. Force
• D. Momentum

Answer: (A)

Energy is the term for the ability to do work. Work happens when a force moves something over a distance, and energy is the capacity that enables that action. Different forms of energy—kinetic, potential, chemical, electrical—represent stored or usable ability to produce change, such as a moving train using electrical energy to drive motors or conserve energy in storage. If you want to know how quickly that work can be done, you look at power, which is the rate of energy transfer. The other terms describe different ideas: force is the push or pull that could cause motion but doesn’t by itself quantify how much work can be done; momentum is about the motion of a body (mass times velocity) and its resistance to changes in motion. In practice, energy (measured in joules or kilowatt-hours in electrical contexts) is the quantity that represents the ability to do work.