Which of the following best describes inertia?

Inertia is best described as the resistance of an object to change its motion. This concept stems from Newton's First Law of Motion, which states that an object at rest will remain at rest and an object in motion will continue to move at a constant velocity unless acted upon by an external force. Essentially, inertia is the property of matter that quantifies how much an object resists changes to its state of motion.

The more mass an object has, the greater its inertia, meaning it requires more force to alter its motion—whether to get it moving from a standstill or to change its speed or direction when it is already in motion. Thus, the definition highlighting resistance accurately encapsulates the concept of inertia and its fundamental role in understanding motion in physical science.