The law of inertia, also known as Newton's first law of motion, states that an object at rest will remain at rest, and an object in motion will continue moving at a constant speed in a straight line unless acted upon by an external force. This means that an object will not change its state of motion unless a force causes it to do so
. Inertia is the natural tendency of objects to resist changes in their motion. The more massive an object is, the greater its inertia, meaning it is more resistant to changes in motion
. For example, a bowling ball has much more inertia than a golf ball because of its greater mass
. The law of inertia was first formulated by Galileo Galilei, who showed through experiments that a body in motion would remain in motion unless a force like friction caused it to stop. René Descartes later generalized this principle. Isaac Newton formalized it as his first law of motion, which is fundamental to classical mechanics
. In summary:
- An object remains at rest or moves uniformly in a straight line unless a force acts on it.
- Inertia is the property of matter that resists changes in motion.
- Mass is a measure of an object's inertia.
- The law was developed through the work of Galileo, Descartes, and Newton.
This principle explains everyday observations and is foundational to understanding motion in physics
