Middle School Physical Science: Motion - Distance and Direction — Flashcards

The direction is the position of an object relative to another or in any universal frame, Distance is the measure of total length between two points relative to each other.

Frame of Reference    
Assume that a school bus passes by as you stand on the sidewalk. It's obvious to you that the bus is moving. It is moving relative to you and the trees across the street. But what about to the children inside the bus? They aren't moving relative to each other. If they look only at the other children sitting near them, they will not appear to be moving. They may be able to tell that the bus is moving only by looking out the window and seeing you and the trees whizzing by.    
This example shows that how we perceive motion depends on our frame of reference. Frame of reference refers to something that is not moving with respect to an observer that can be used to detect motion. For the children on the bus, if they use other children riding the bus as their frame of reference, they do not appear to be moving. But if they use objects outside the bus as their frame of reference, they can tell they are moving.