Displacement (symbolized d or s ), also called length or distance, is a one-dimensional quantity representing the separation between two defined points. The standard unit of displacement in the International System of Units ( SI ) is the meter (m).
Displacement is usually measured or defined along a straight line. For example, we might speak of the distance between the center of the earth and an orbiting satellite , and measure it as 13,000,000 meters. However, displacement is sometimes measured or defined along curved paths. The most common example is in expressions of the distance between geographic locations on the earth's surface; the equator is approximately 10,000,000 meters from the North Pole, for example. Other examples of nonlinear displacement include the circumference of a subatomic particle, the actual length (as opposed to the straight span) of a sagging rope, or the length of wire that comprises a coil.
When expressing large or small distances, prefix multiplier s are attached to the meter. The table below shows the most common alternative displacement units and their relationship to the meter.
|To convert to
|10 -6||10 6|
|nanometer (nm)||10 -9||10 9|
|Angström (Ä)||10 -10||10 10|