In this document, we will try to answer a fundamental question of physical science, "Why do things start to move, slow down, speed up, stop moving or change direction?" In answering these core questions we can develop concepts that can...

Review the key concepts, equations, and skills for friction, including how to find the direction and magnitude of the friction force.

This article on Khan Academy is about air and fluid resistance that is caused by friction.

Newton's First Law also called the law of inertia is the most important thing to realize about motion. This article offers more information on motion and explains solved problems involving Newton's First Law. Also included is a video...

A short biography about Charles Coulomb, known for developing Coulomb's law, the definition of the electrostatic force of attraction and repulsion.