Final answer:
Inertia is the measure of an object's resistance to changes in its state of motion, and it is quantified by the object's mass. Mass does not change with location and is fundamental to Newtonian physics for understanding motion and force.
Step-by-step explanation:
The measure of resistance an object has to a change in its state of motion is called inertia, which is directly related to the object's mass. In Newtonian physics, inertia is the tendency of an object to remain at rest or to continue moving at a constant velocity unless acted upon by a force. Mass is a measure of the amount of matter in an object, and it is this property that quantifies an object's inertia. Unlike weight, mass is consistent across different locations, such as on Earth or on the Moon. Generally, an object with more mass requires more force to change its state of motion. For example, a large boulder has more inertia than a basketball and, therefore, is harder to set in motion or come to a stop.
When comparing objects of equal mass, such as a kilogram of cotton balls and a kilogram of gold, they have the same mass and inertia, despite having different volumes and densities. The mass of objects is typically measured by comparison with standard kilograms, making it a fundamental property in physics for understanding motion.