For the convenience of the first-time student, a glossary of terms is included here.
Kinematics from the Greek kinema (movement) is the consideration of how things move without regard to the forces that cause the objects to move the way they do. In an introductory survey course such as this one, it is customary to begin with the simplest, most well-behaved situations. This is accomplished by neglecting at least initially forces such a sliding- or fluid friction, or by assuming that accelerations are uniform when often in nature they are not. Gradually our attention will turn to objects that move by action of more complicated forces.
The jargon of kinematics can be confusing to the casual scholar; let's try to sort things out. All of the quantities that are measured in nature can be classified into two categories--vectors and scalars.
Vectors are things that have a size and a spatial direction. It is important to note that each part of this dual nature is equally important. Picture yourself on a treasure hunt, say from the front door of the school.If you are told how far to walk, but given no direction, finding the treasure is not possible. Or given a direction, but no definite distance, your chance of finding treasure is zero.In either scenario, you are lacking the requisite information to find the treasure. A definite distance in a given direction (something called displacement on the next page) gets us to the treasure.
Scalars on the other hand have a size only; spatial direction is immaterial. Perhaps you wish to walk for exercise. How far you walk is important; the direction is relatively insignificant. The reader will need to pay careful attention to the terminology used in this first encounter with vectors and scalars. Some terms such as speed and velocity, while used interchangeably in common conversation, have very strict definitions in physics.
Units are also important,
not only to describe the quantity at hand, but also to provide
a safety net to ensure that the answer to a question or problem
is correct. Paying attention to units was important in other
science classes; it is most important here. In fact, for anything
that you pass in to me for credit, the rule here is no units
= no credit
This page was last reviewed by MEG 01/20/09