Which of the following describes energy of motion that performs work?

The concept of energy associated with motion is fundamentally described as kinetic energy. When motion is involved in performing work, this is specifically referred to as mechanical kinetic energy. This type of energy arises from the movement of objects, which can exert forces on other objects or systems to perform work.

For example, when a car moves down the street, its mechanical kinetic energy is what allows it to apply force on components like the brakes or the road itself, demonstrating its capacity to do work. In mechanical systems, energy transformation is common; kinetic energy can convert to potential energy and vice versa, but the definition of kinetic energy is strictly related to motion.

The other types of energy mentioned—like electrical, thermal, and potential energy—do not fit the specific definition of energy in motion meant to perform work in a mechanical context. While they may involve movement or energy transformations, they are characterized by different properties and roles within energy systems.