What term describes the tendency of an object to resist changes in its motion?

The term that describes the tendency of an object to resist changes in its motion is inertia. Inertia is a fundamental property of matter, defined by Newton's First Law of Motion, which states that an object will remain at rest or continue moving at a constant velocity unless acted upon by a net external force. This means that an object at rest will stay at rest, and an object in motion will maintain its state of motion unless something causes it to change.

Inertia is directly related to the mass of an object; the greater the mass, the greater the inertia, meaning a more massive object will be harder to start moving or to stop once it is moving. Recognizing inertia is essential in understanding how forces interact with objects and how they behave under various conditions, making it a fundamental concept in physics.