“In physics there are these important things called vectors. A vector is simply something that has magnitude and direction.”

– Basic Kinematics

In a previous chapter of study, the variety of ways by which motion can be described (words, graphs, diagrams, numbers, etc.) was discussed. In this unit (Newton’s Laws of Motion), the ways in which motion can be explained will be discussed. Isaac Newton (a 17th century scientist) put forth a variety of laws which explain why objects move (or don’t move) as they do. These three laws have become known as Newton’s three laws of motion. The focus of Lesson 1 is Newton’s first law of motion – sometimes referred to as the law of inertia.

Newton’s first law of motion is often stated as

An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force.