LAW OF INERTIA

PRERNA FOR IAS

LAW OF INERTIA

1. Newton’s First Law of Motion (Law of Inertia)

Newton’s First Law of Motion, also known as the Law of Inertia, states that an object will remain at rest or continue moving with constant velocity unless acted upon by an external force. This law was formulated by Isaac Newton and forms the foundation of classical mechanics. The law explains why objects do not change their state of motion on their own. Inertia is the natural tendency of matter to resist changes in motion. The greater the mass of an object, the greater its inertia. This principle helps explain many everyday observations involving motion and rest.

2. Object at Rest

An object at rest remains at rest when no net external force acts upon it. For example, a book lying on a table does not move because all forces acting on it are balanced. Gravity pulls the book downward, while the table exerts an equal upward force. Since the net force is zero, the object remains stationary. This demonstrates inertia of rest, which is the tendency of an object to resist any change from its state of rest. Everyday examples include parked vehicles, furniture, and stationary objects. A force must be applied to make such objects start moving.

3. Object in Mo