Energy is defined as?

• A. The energy stored in an object due to motion.
• B. The mass of an object.
• C. The capacity to cause change.
• D. The ability to do work.

Answer: (D)

Energy is the ability to do work. In physics, work means applying a force to move something over a distance. If a system has energy, it can cause changes—like moving an object, lifting a weight, or warming a substance—by doing work or by transferring heat. Energy comes in many forms, such as kinetic (motion), potential (position), chemical, thermal, and electrical, and it can be transformed from one form to another while the total amount in a closed system stays the same. The idea described as the energy stored in an object due to motion is a specific form (kinetic energy), not the broad definition of energy. Mass is not energy, and a vague “capacity to cause change” is related but not the precise physics definition.