Re: displacement and graphs

["RAUBER, JOEL" <JOEL_RAUBER@SDSTATE.EDU>]

> I have found the same confusion seems to exist in various
> authors' minds,
> and consequently I have to make a lengthy explanation about
> the terms.  But
> I'd still be interested in what the rest of the list does.
>
> Does the term "displacement" refer to the vector r (from some
> arbitrary
> origin) or does it refer to r_2 - r_1  (i.e. final -
> initial).  They are
> clearly not the same thing but it seems texts use
> "displacement" for both
> concepts.

What I do:

Displacement: necessarily means displacement over an interval:

Which is r_2 - r_1

Position:  the position of an object I define as its displacement from an
arbitrary origin:  which is to say for Position I set r_1 equal to the
origin.

Joel Rauber