inertia

Type: Concept

As of November 2026, inertia has been mentioned in one podcast episode on Stuff You Should Know (Dec 2025).

Inertia is the natural tendency of objects in motion to stay in motion and objects at rest to stay at rest, unless a force causes its velocity to change. It is one of the fundamental principles in classical physics, and is described by Isaac Newton in his first law of motion. It is one of the primary manifestations of mass, one of the core quantitative properties of physical systems. Newton writes:LAW I. Every object perseveres in its state of rest, or of uniform motion in a right line, except i