Title: Background Information
Course: Web Tools for Courses

Background

In a universe full of motion, change is inevitable. Luckily, we find that some motions—like a planet orbiting the sun—are relatively constant and repetitive, and obey natural laws that we can come to understand through measurement and mathematical principles. Kinematics is a branch in the study of physics which deals with the quantitative descriptions of motion. Understanding the motions which characterize certain objects allows us to deduce where objects might have been in the past and where they may be in the future, based just on our observation of the object’s motion in the present.

Formulae help us quantitatively express an object’s motion. For example, if an object is moving with a constant speed, we express the object’s motion as the rate of change of the object’s position “d” with respect to change in time “t,” and give that rate a name called speed “s.” We can reduce this definition for speed to the simple formula:

Drawing pictures can help us understand the relationships between the motions of different objects. Even better, a series of pictures can tell us qualitatively where an object is moving and where it has been.