What does inertia refer to in physical terms?

In physical terms, inertia refers to the property of an object to resist changes in its state of motion. This means that an object at rest will stay at rest, and an object in motion will continue to move at a constant velocity unless acted upon by an external force. This concept is fundamental in understanding Newton's First Law of Motion, which states that an object will not change its motion unless a net force acts on it. Inertia is directly related to mass: the greater the mass of an object, the greater its inertia and the more force it will take to change its motion.

The other options do not accurately describe inertia. The attraction between two masses relates to gravitational force, while the force exerted by gravity pertains to weight. The energy of a vibrating object refers to kinetic energy or potential energy associated with its motion and position, not inertia. Therefore, the tendency to remain in motion or at rest is the correct characterization of inertia.