The position of an object is, well, simply a description of its location in space. For example, in the picture below, the butterfly is "on a pink flower."
Image courtesy of
Wikipedia
There isn't much math in a simple position.
But when an object moves from one location to another, we can start using quantitative descriptions. In the example below, the butterfly makes a twisty, looping journey from the pink flower to the white flower. Measuring the curvy length of its path will reveal the distance it travelled.
Images courtesy of
Wikipedia
and
Wikipedia
The displacement is defined as the straight-line distance from the starting point to the end point of its journey.
Images courtesy of
Wikipedia
and
Wikipedia
Q: What are the units of displacement?
Right. The standard SI units of displacement are meters, but we might use other units in certain circumstances:
Q: What would be a good choice of units to describe the motion of paramecium inside a drop of water? Q: What would be a good choice of units to describe the motion of a star through our Milky Way Galaxy?
Copyright © Michael Richmond. This work is licensed under a Creative Commons License.