A clear explanation of Newton's First Law of Motion, the law of inertia, with diagrams and real-world examples. Useful for both students and teachers. Written by a high school physics teacher.

Through illustrated examples and interactive practice problems, students explore the relationship of inertia and mass.

Do you need to review any of Newton's three laws? This website contains a video collection on Newton's Law from a physics course at East Los Angeles College. In twelve lectures, each law is explained with examples. Also discussed is...

This lesson focuses on Newton's First Law: an object remains in the same state of motion unless a resultant force acts on it. If the resultant force on an object is zero, this means: a stationary object stays stationary; a moving object...

This article on weight will help you prepare for the AP Physics test. Included are example problems to help you practice.

Through illustrated examples and practice problems, students explore the centripetal force requirement. So for an object moving in a circle, there must be an inward force acting upon it in order to cause its inward acceleration.