Inertia

Definition

Inertia is the resistance of an object to any change in its state of motion. It is directly proportional to the mass of the object.

5 Must Know Facts For Your Next Test

1. Inertia is described by Newton's First Law of Motion.
2. An object at rest will stay at rest unless acted upon by an external force, due to inertia.
3. An object in motion will stay in motion with the same speed and direction unless acted upon by an external force.
4. The greater the mass of an object, the greater its inertia.
5. Inertia does not depend on velocity but solely on mass.

Review Questions

• What law of motion describes inertia?
• How does mass influence inertia?
• What happens to an object's state of motion if no external forces act on it?

Related terms

Force:

A push or pull acting upon an object resulting from its interaction with another object.

Mass:

A measure of the amount of matter in an object, which directly influences its inertia.

Newton's First Law:

The principle stating that an object will remain at rest or move in a straight line at constant speed unless acted upon by a net external force.