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Re: vector components and notation

Sorry, John - but my email software did not properly translate your html code
- odd, because the code looks fine. However, I could get the point of what you
are saying. Yes, Serway does use the two vectors Ax and Ay - however, he is
careful not to use the word "component" until he actually defines the term
from the scalar lengths of those vectors. Then he drops the vectors Ax and Ay
completely throughout the remainder of the text and only uses scalar
components. I think his presentation could have been even stronger by leaving
out those two vectors entirely - I think that was your objection and I agree
with you. Do you have favorite textbooks that you feel take a clearer
approach? I hope your not a textbook author and I'm saying something rather
dumb here :-)

Bob at PC

John Mallinckrodt wrote:

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<div>At 6:14 PM -0400 9/16/02, Bob LaMontagne wrote:</div>
<div><br></div>
<blockquote type="cite" cite>One of the reasons that I have used
Serway (Physics for Scientists and Engineers) is because I feel he is
one of the few authors who really presents the concept of components
correctly and also very clearly explains the concept to the student.&nbsp;
...</blockquote>
<div><br></div>
<div>I have problems with Serway's approach because the notation is
inherently inconsistent.&nbsp; He defines<i> A</i> as the magnitude
of<b> A</b>.&nbsp; He then defines the *vectors*<b> A</b>_x and<b>
A</b>_y.&nbsp; Logically, therefore,<i> A</i>_x and<i> A</i>_y would
be the *magnitudes* of the vectors<b> A</b>_x and<b> A</b>_y.&nbsp;
But in the next breath they are defined instead as the ordinary signed
scalar components of the vector<b> A</b>.</div>
<div><br></div>
<div>While I like the idea of being able to talk about *vector*
components as well as *scalar* components, I think it almost
inevitably leads either to notational awkwardness or inconsistency,
both of which are potentially confusing to students.</div>
<div><br></div>
<div>John</div>
<x-sigsep><pre>--
</pre></x-sigsep>
<div>&nbsp;&nbsp; A. John
Mallinckrodt&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
http://www.csupomona.edu/~ajm<br>
&nbsp;&nbsp; Professor of Physics&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
mailto:ajm@csupomona.edu<br>
&nbsp;&nbsp; Physics
Department&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
voice:909-869-4054<br>
&nbsp;&nbsp; Cal Poly
Pomona&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<span
</span>&nbsp;&nbsp;&nbsp; fax:909-869-5090<br>
&nbsp;&nbsp; Pomona, CA 91768-4031&nbsp;&nbsp;&nbsp;&nbsp;
office:Building 8, Room 223</div>
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