What is the definition of inertia?

Inertia is defined as the tendency of an object to resist changes in its state of motion. This means that an object at rest will remain at rest unless acted upon by an external force, and an object in motion will continue moving at a constant velocity in a straight line unless a force causes it to change speed or direction. This principle is grounded in Newton’s first law of motion, which highlights that the natural state of objects is to maintain their current state—whether that’s stationary or moving uniformly—unless influenced by some external force.

This understanding of inertia is fundamental to safe driving practices, as it helps drivers anticipate how their vehicle and other moving objects will behave under different circumstances. Recognizing that inertia affects stopping distances, turning maneuvers, and the potential impact of sudden braking can significantly enhance a driver's ability to navigate safely and effectively.