The study of motion is often called kinematics. We will begin
our study with one dimensional kinematics. We will later expand
to 2 and 3 dimensional kinematics after we have studied vectors.
We can give the position of an object in relation to a reference
point. There are a number of variables we can use for position,
such as x, d, or s. The official metric unit for position is the
meter (abbreviated m). The meter was first defined in terms of
the circumference of the Earth on a meridian passing through
Paris. It is now defined in terms of the speed of light. When
working with other scales, it might be convenient to use other
metric units such as the nanometer (nm), the centimeter (cm),
and the kilometer (km). We will often use exponential notation.
Exponential notation is convenient for expressing very large and
small numbers. For instance, 12,300 would be expressed as 1.23 x
10,000 or 1.23 x 104 So 3.14 km = 3140 m = 3.14 x 103 m For
small numbers, 0.000345 = 3.45 x 10-4 A micrometer, 1 μm = 10-6
m The widt