The first law of motion, often called the law of inertia, is named so because it describes the tendency of an object to resist changes in its state of motion.

Here's a breakdown:

* Inertia: The inherent property of an object to resist changes in its motion. It's the tendency to stay at rest or continue moving at a constant velocity.

* First Law of Motion: States that an object at rest will stay at rest, and an object in motion will stay in motion at a constant velocity, unless acted upon by a net external force.

Essentially, the first law describes inertia in action. It's the reason why:

* A ball sitting on a table doesn't spontaneously start rolling.

* A car in motion keeps moving at a constant speed unless the brakes are applied or the engine provides more power.

* A passenger in a car continues to move forward when the car suddenly stops, unless restrained by a seatbelt.

Therefore, the first law of motion and the concept of inertia are intrinsically linked. The first law explains the phenomenon of inertia, and the term "inertia" captures the essence of the law itself.