What best defines the term "mechanical energy"?

Mechanical energy is best defined as the sum of potential energy and kinetic energy in a system. This encompasses all forms of energy associated with the motion and position of objects. Kinetic energy is the energy an object possesses due to its motion, while potential energy is the stored energy based on an object's position or configuration in a force field, such as gravitational force.

When you combine these two forms of energy, you get mechanical energy, which indicates the total energy in a system that can be used to do work. This definition is foundational in mechanics, as it illustrates how energy is conserved and transformed between states. Other choices focus on only one aspect of energy (either motion or position) or refer to electrical systems, which do not pertain to the mechanical context of energy being considered. Hence, the correct definition captures the comprehensive nature of mechanical energy as the overall capability of a system to perform work through its motion and positional configuration.