In the world of Physics, Sir Isaac Newton is the man who pioneered classical physics with his laws of motion. In these laws, the first law is also known as the Law of Inertia . Law of inertia is the most important and renowned one. In this piece of article, let us discuss the first law of inertia in detail. Before discussing the law of inertia , let us know the Inertia Definition . Inertia is defined as a property of matter by which it remains at the state of rest or in uniform motion in the ... Inertia , property of a body by virtue of which it opposes any agency that attempts to put it in motion or, if it is moving, to change the magnitude or direction of its velocity. It is a passive property and does not enable a body to do anything except oppose such active agents as forces and torques. Inertia is the natural tendency of objects to stay in motion or rest unless a force acts on them. Learn about the origin and development of the concept of inertia from ancient philosophers to Newton's first law of motion. 2 meanings: 1. the state of being inert; disinclination to move or act 2. physics a. the tendency of a body to preserve its.... Click for more definitions.