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Re: Displacement



I have had a few students ask this question. This is how I had them do
the analysis:

To return to where you started, you first had to go somewhere. To get a
displacement of zero, you had to add the vectors together to get that
zero. Now, if you are adding vectors, you either treat them as
components in a cartesian (generally) plane, or by magnitude and angle.

So, simply add the vectors together, and see what you get...

It rarely ever fails that they get the correct answer, and the angle
answer generally comes out to 0 degrees.

Now, I have asked my math colleages about this, and they say that 0
magnitude with 0 degrees makes perfect mathematical sense to them.
So.... I'm happy enough to leave it at that -- unless someone else has a
better answer?

Peter Schoch
SCCC


Charlie Payne wrote:

Listers:
Although this may be trivial, I have a question concerning displacement.
Many of our textbooks define displacement as a vector with distance as
magnitude and some direction from a designated point, or as simply a change
in position. I understand that if a body returns precisely to the original
reference point, then its displacement is zero. My question concerns
direction. If a vector must have direction, and displacement is a vector,
how should one describe the displacement of a body that returns to its
starting point? I am a non-physics major who'd appreciate a kind response!
Thanks.
Charlie Payne
Northern HS
Durham, NC