All are familiar with one of the many definitions given in the works on physics, of the term Vis Inertia— a want of power in a body to move itself when at rest or to come to rest when in motion.

Facing the Inquisition for his scientific beliefs, Galileo developed many important ideas about the science of motion, such as inertia. Isaac Newton built on many of Galileo's insights when ...

The natural tendency of objects to resist a change in their state of rest or of uniform motion is called inertia. • The mass of an object is a measure of its inertia. Its SI unit is kilogram (kg).