What is the Difference Between Newton’s First Law and Inertia?

🆚 Go to Comparative Table 🆚

The difference between Newton's first law and inertia lies in their descriptions and the concepts they cover. Newton's first law of motion states that an object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted upon by an unbalanced force. In other words, it describes the relationship between the motion of an object and the external forces acting on it.

On the other hand, inertia refers to the tendency of an object to resist changes in its state of motion. It is a property of matter and is related to an object's mass. Inertia is the reason behind the observation that objects in motion tend to stay in motion, and objects at rest tend to stay at rest, unless acted upon by an external force.

In summary:

  • Newton's first law of motion describes the behavior of objects in the absence of external forces and explains how they maintain their state of motion.
  • Inertia is the property of matter that causes objects to resist changes in their state of motion.

Comparative Table: Newton’s First Law vs Inertia

Here is a table comparing Newton's First Law and Inertia:

Newton's First Law of Motion (Law of Inertia) Inertia
States that a body at rest remains at rest, or if in motion, remains in motion at a constant velocity unless acted on by a net external force. The tendency of an object to remain at rest or remain in motion is called inertia.
Also known as the law of inertia. Inertia is related to an object's mass.
An object at rest remains at rest, or if in motion, remains in motion at a constant velocity when there is no net external force acting on it. An object with more mass has more inertia.
The law is applicable when the forces acting on an object are balanced, i.e., there is no net external force.

In summary, Newton's First Law of Motion, also known as the Law of Inertia, describes the behavior of objects when there is no net external force acting on them. Inertia, on the other hand, is the tendency of an object to remain at rest or remain in motion, and it is related to the object's mass.