# Inertia

## Contents

## Explanation[edit]

Inertia of an object is defined as the resistance to the change of its state of motion, direction or rest. As explained by the law of inertia (Newton's first law) inertia can be expressed as a property of an object in motion with a constant velocity and a constant direction that resists the changes in its state of motion when acted upon by an unbalanced force. Inertia can be further explored by reading the concepts of physical reference frames.

## Frequently Asked Questions[edit]

### What is an inertial mass?[edit]

Inertial mass is the mass that you measure as an object resists its acceleration. The mass that would be deduced from Newton's second law, **F= ma** is in fact, an inertial mass.

### What is a moment of inertia?[edit]

Moment of inertia is the inertia of an object that rotates about an axis. Just like an inertia, the moment of inertia is the resistance of that rotating object to any angular acceleration and deceleration.