Inertia is the tendency of objects to maintain their state of motion (resist accelerations). This idea is essential for understanding motions on Earth but it is often counter-intuitive.

The Earth spins on its axis, completing a full revolution every day. By why does it do this? One of the most common misconceptions in physics is the belief that constant motion requires a constant force. So many people believe there must be some force in the Earth (e.g. gravity, centrifugal force) that keeps it spinning. In truth, no force is required because a fundamental property of mass is that it maintains its state of motion in the absence of external forces. This property is called inertia.

Have you tried this resource?

Help someone out by sharing your thoughts!

Write a review

Have questions about K-12 education?

Ask our community of thousands of teachers, homeschoolers, and parents! Or see recently-asked questions.

Ask a Question

More Ways to Learn Force & Motion


Forces and Newton's laws of motion

High School - College | Online class

This tutorial will expose you to the foundation of classical mechanics—Newton’s laws. On one level they are intuitive, on another lever they are completely counter-intuitive. Challenge your take on...


Engineering Systems in Motion: Dynamics of Particles and Bodies in 2D Motion

College | Online class

This course is an introduction to the study of bodies in motion as applied to engineering systems and structures. We will study the dynamics of particle motion and bodies in rigid planar (2D)...


Meet Science: Force & Motion

4th - 6th | iPhone/iPad

What a fun way to learn science and endorse curiosities with animations, experiments and mini-games! Introducing the 3rd version of ‘Meet Science’ series, Force and Motion edition! ■ Best Way to...


Advanced Engineering Systems in Motion: Dynamics of Three Dimensional (3D) Motion

College | Online class

This course is an advanced study of bodies in motion as applied to engineering systems and structures. We will study the dynamics of rigid bodies in 3D motion. This will consist of both the...

See all resources for Force & Motion

Links to supporting retailers are recognized and built automatically, so we can provide you with truly unbiased listings.
We receive a small share of sales from those links to help us keep this service free for all learners. Thanks for your support!

Frequently Asked Questions

What is Inertia by Veritasium?

Inertia is a learning resource for Force & Motion. It is available in the following format(s): Online/YouTube video. It is suited for 6th - College students.

What grade level is Inertia by Veritasium appropriate for?

It is designed for 6th - College students, but could be useful for students of other ages as well; please look at the description and images to determine suitability.

How much does Inertia by Veritasium cost?

It is free!