<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>1870-3542</journal-id>
<journal-title><![CDATA[Revista mexicana de física E]]></journal-title>
<abbrev-journal-title><![CDATA[Rev. mex. fís. E]]></abbrev-journal-title>
<issn>1870-3542</issn>
<publisher>
<publisher-name><![CDATA[Sociedad Mexicana de Física]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S1870-35422009000100015</article-id>
<title-group>
<article-title xml:lang="en"><![CDATA[Students' difficulties with tension in massless strings. Part II]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Flores-García]]></surname>
<given-names><![CDATA[S.]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Esparza]]></surname>
<given-names><![CDATA[A.E.]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Chávez-Pierce]]></surname>
<given-names><![CDATA[J.E.]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Hernández-Palacios]]></surname>
<given-names><![CDATA[A.A.]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Luna-González]]></surname>
<given-names><![CDATA[J.]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Estrada-Saldaña]]></surname>
<given-names><![CDATA[J.F.]]></given-names>
</name>
<xref ref-type="aff" rid="A01"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[González-Quezada]]></surname>
<given-names><![CDATA[M.D.]]></given-names>
</name>
<xref ref-type="aff" rid="A02"/>
</contrib>
</contrib-group>
<aff id="A01">
<institution><![CDATA[,Universidad Autónoma de Ciudad Juárez  ]]></institution>
<addr-line><![CDATA[Ciudad Juárez Chih.]]></addr-line>
</aff>
<aff id="A02">
<institution><![CDATA[,Instituto Tecnológico de Ciudad Juárez  ]]></institution>
<addr-line><![CDATA[Ciudad Juárez Chih.]]></addr-line>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>06</month>
<year>2009</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>06</month>
<year>2009</year>
</pub-date>
<volume>55</volume>
<numero>1</numero>
<fpage>118</fpage>
<lpage>131</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S1870-35422009000100015&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S1870-35422009000100015&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S1870-35422009000100015&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Muchos estudiantes de los cursos introductorios de mecánica presentan serias dificultades para comprender el concepto de fuerza como vector en el contexto de la tensión en cuerdas de masa despreciable. Una de las posibles causas es la falta de entendimiento funcional desarrollado durante las clases fundamentadas en una enseñanza tradicional. En este artículo presentamos una colección de este tipo de problemas de aprendizaje que tienen los alumnos pertenecientes a los cursos de física clásica y estática en la Universidad Estatal de Nuevo México, en la Universidad Estatal de Arizona y en la Universidad Autónoma de Ciudad Juárez. Estas dificultades de aprendizaje se obtuvieron durante una investigación conducida tanto en laboratorios como en el salón de clases. En esta segunda parte de la investigación se abordan problemas de entendimiento relacionados con el efecto del ángulo en la tensión y el argumento de "compensación".]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Many students enrolled in the introductory mechanics courses have learning difficulties related to the concept of force in the context of tension in massless strings. One of the potential causes could be a lack of functional understanding through a traditional instruction. In this article, we show a collection of this kind of students' difficulties at the New México State University, at the Arizona State University, and at the Independent university of Ciudad Juárez in México. These difficulties were collected during an investigation conducted no only in lab sessions but also in lecture sessions. In this second part of the investigation we show understanding difficulties related to the effect of the angle on tension and the "compensation arguments"]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[Tensión]]></kwd>
<kwd lng="es"><![CDATA[fuerzas en cuerdas]]></kwd>
<kwd lng="es"><![CDATA[dificultades de aprendizaje]]></kwd>
<kwd lng="es"><![CDATA[fuerza como una tensión]]></kwd>
<kwd lng="en"><![CDATA[Tension]]></kwd>
<kwd lng="en"><![CDATA[forces in strings]]></kwd>
<kwd lng="en"><![CDATA[learning difficulties]]></kwd>
<kwd lng="en"><![CDATA[force as a tension]]></kwd>
</kwd-group>
</article-meta>
</front><body><![CDATA[ <p align="justify"><font face="verdana" size="4">Ense&ntilde;anza</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="center"><font face="verdana" size="4"><b>Students' difficulties with tension in massless strings. Part II</b></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="center"><font face="verdana" size="2"><b>S. Flores&#150;Garc&iacute;a&ordf;, A.E. Esparza&ordf;, J.E. Ch&aacute;vez&#150;Pierce&ordf;, A.A. Hern&aacute;ndez&#150;Palacios&ordf;, J. Luna&#150;Gonz&aacute;lez&ordf;, J.F. Estrada&#150;Salda&ntilde;a&ordf; and M.D. Gonz&aacute;lez&#150;Quezada<sup>b</sup></b></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><i>&ordf; Universidad Aut&oacute;noma de Ciudad Ju&aacute;rez, Avenida del Charro 450 Nte. Col. Partido Romero 32310 Ciudad Ju&aacute;rez Chih.</i></font></p>     <p align="justify"><font face="verdana" size="2"><i><sup>b</sup> Instituto Tecnol&oacute;gico de Ciudad Ju&aacute;rez, Avenida Tecnol&oacute;gico 1340 Fracc. Crucero 32500 Ciudad Ju&aacute;rez Chih.</i></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2">Recibido el 27 de marzo de 2008    ]]></body>
<body><![CDATA[<br>   Aceptado el 3 de abril de 2009</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>Resumen</b></font></p>     <p align="justify"><font face="verdana" size="2">Muchos estudiantes de los cursos introductorios de mec&aacute;nica presentan serias dificultades para comprender el concepto de fuerza como vector en el contexto de la tensi&oacute;n en cuerdas de masa despreciable. Una de las posibles causas es la falta de entendimiento funcional desarrollado durante las clases fundamentadas en una ense&ntilde;anza tradicional. En este art&iacute;culo presentamos una colecci&oacute;n de este tipo de problemas de aprendizaje que tienen los alumnos pertenecientes a los cursos de f&iacute;sica cl&aacute;sica y est&aacute;tica en la Universidad Estatal de Nuevo M&eacute;xico, en la Universidad Estatal de Arizona y en la Universidad Aut&oacute;noma de Ciudad Ju&aacute;rez. Estas dificultades de aprendizaje se obtuvieron durante una investigaci&oacute;n conducida tanto en laboratorios como en el sal&oacute;n de clases. En esta segunda parte de la investigaci&oacute;n se abordan problemas de entendimiento relacionados con el efecto del &aacute;ngulo en la tensi&oacute;n y el argumento de "compensaci&oacute;n".</font></p>     <p align="justify"><font face="verdana" size="2"><b>Descriptores:</b>   Tensi&oacute;n; fuerzas en cuerdas; dificultades de aprendizaje; fuerza como una tensi&oacute;n.</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>Abstract</b></font></p>     <p align="justify"><font face="verdana" size="2">Many students enrolled in the introductory mechanics courses have learning difficulties related to the concept of force in the context of tension in massless strings. One of the potential causes could be a lack of functional understanding through a traditional instruction. In this article, we show a collection of this kind of students' difficulties at the New M&eacute;xico State University, at the Arizona State University, and at the Independent university of Ciudad Ju&aacute;rez in M&eacute;xico. These difficulties were collected during an investigation conducted no only in lab sessions but also in lecture sessions. In this second part of the investigation we show understanding difficulties related to the effect of the angle on tension and the "compensation arguments"</font></p>     <p align="justify"><font face="verdana" size="2"><b>Keywords:</b>   Tension; forces in strings; learning difficulties; force as a tension.</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     ]]></body>
<body><![CDATA[<p align="justify"><font face="verdana" size="2">PACS: 01.40.d; 01.40.Fk; 01.49.Ha</font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><a href="/pdf/rmfe/v55n1/v55n1a15.pdf" target="_blank">DESCARGAR ART&Iacute;CULO EN FORMATO PDF</a></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b><a href="/img/revistas/rmfe/v55n1/a15a1.jpg" target="_blank">Appendix</a></b></font></p>     <p align="justify"><font face="verdana" size="2">&nbsp;</font></p>     <p align="justify"><font face="verdana" size="2"><b>References</b></font></p>     <!-- ref --><p align="justify"><font face="verdana" size="2">1. E. F. Redish, J.M. Saul, and R.N. Steinberg, <i>Am. J. Phys. </i><b>66</b> (1998) 212.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8450907&pid=S1870-3542200900010001500001&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">2. S. Flores, S. Kanim, and H. Kautz, <i>Am. J. Phys. </i><b>72</b> (2004) 460.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8450908&pid=S1870-3542200900010001500002&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">3. S. Flores, "Student use of vectors in mechanics", PhD. Dissertation, Department of Physics, New M&eacute;xico State University, 2006.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8450909&pid=S1870-3542200900010001500003&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">4. S. Sjoberg and S. Lie, " Ideas about force and movement among Norwegian pupils and students", Report 81&#150;11, The Centre for School Science, University of Oslo, Blindere, Oslo 3, Norway, 1981.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8450910&pid=S1870-3542200900010001500004&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">5. R.F. Gunstone and R.T. White, <i>Sci. Educ. </i><b>65</b> (1981) 291.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8450911&pid=S1870-3542200900010001500005&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">6. A. Arons, <i>A guide to Introductory Physics Teaching </i>(Wiley, New York, 1990).</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8450912&pid=S1870-3542200900010001500006&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">7. L.C. McDermott, P.S. Shaffer, and M.D. Somers, <i>Am. J. Phys. </i><b>62</b> (1994) 46.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8450913&pid=S1870-3542200900010001500007&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">8. L.C. McDermott, P. Shaffer, and the Physics Education Group at the University of Washington,  <i>Tutorials in Introductory Physics </i>(Prentice&#150;Hall, New Jersey, 2002).</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8450914&pid=S1870-3542200900010001500008&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">9. T.O'Brien Pride, S. Vokos, and L.C. McDermott, <i>Am. J. of Phys. </i><b>66</b> (1998) 147.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8450915&pid=S1870-3542200900010001500009&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">10. C.H. Kautz, P.R.L. Heron, M.E. Loverude, and L.C. McDermott, <i>Am. J. of Phys.</i> <b>73</b> (2005) 1055.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8450916&pid=S1870-3542200900010001500010&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --><!-- ref --><p align="justify"><font face="verdana" size="2">11. S. Flores <i>et al., CULCYT </i><b>5</b> (2008) 19.</font>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;[&#160;<a href="javascript:void(0);" onclick="javascript: window.open('/scielo.php?script=sci_nlinks&ref=8450917&pid=S1870-3542200900010001500011&lng=','','width=640,height=500,resizable=yes,scrollbars=1,menubar=yes,');">Links</a>&#160;]<!-- end-ref --> ]]></body><back>
<ref-list>
<ref id="B1">
<label>1</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Redish]]></surname>
<given-names><![CDATA[E. F.]]></given-names>
</name>
<name>
<surname><![CDATA[Saul]]></surname>
<given-names><![CDATA[J.M.]]></given-names>
</name>
<name>
<surname><![CDATA[Steinberg]]></surname>
<given-names><![CDATA[R.N.]]></given-names>
</name>
</person-group>
<source><![CDATA[Am. J. Phys.]]></source>
<year>1998</year>
<volume>66</volume>
</nlm-citation>
</ref>
<ref id="B2">
<label>2</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Flores]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
<name>
<surname><![CDATA[Kanim]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
<name>
<surname><![CDATA[Kautz]]></surname>
<given-names><![CDATA[H]]></given-names>
</name>
</person-group>
<source><![CDATA[Am. J. Phys.]]></source>
<year>2004</year>
<volume>72</volume>
<page-range>460</page-range></nlm-citation>
</ref>
<ref id="B3">
<label>3</label><nlm-citation citation-type="">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Flores]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
</person-group>
<source><![CDATA["Student use of vectors in mechanics"]]></source>
<year></year>
</nlm-citation>
</ref>
<ref id="B4">
<label>4</label><nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Sjoberg]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
<name>
<surname><![CDATA[Lie]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
</person-group>
<source><![CDATA[" Ideas about force and movement among Norwegian pupils and students"]]></source>
<year>1981</year>
<publisher-loc><![CDATA[Oslo ]]></publisher-loc>
<publisher-name><![CDATA[The Centre for School Science, University of Oslo]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B5">
<label>5</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Gunstone]]></surname>
<given-names><![CDATA[R.F.]]></given-names>
</name>
<name>
<surname><![CDATA[White]]></surname>
<given-names><![CDATA[R.T.]]></given-names>
</name>
</person-group>
<source><![CDATA[Sci. Educ.]]></source>
<year>1981</year>
<volume>65</volume>
<page-range>291</page-range></nlm-citation>
</ref>
<ref id="B6">
<label>6</label><nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Arons]]></surname>
<given-names><![CDATA[A]]></given-names>
</name>
</person-group>
<source><![CDATA[A guide to Introductory Physics Teaching]]></source>
<year>1990</year>
<publisher-loc><![CDATA[New York ]]></publisher-loc>
<publisher-name><![CDATA[Wiley]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B7">
<label>7</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[McDermott]]></surname>
<given-names><![CDATA[L.C.]]></given-names>
</name>
<name>
<surname><![CDATA[Shaffer]]></surname>
<given-names><![CDATA[P.S.]]></given-names>
</name>
<name>
<surname><![CDATA[Somers]]></surname>
<given-names><![CDATA[M.D.]]></given-names>
</name>
</person-group>
<source><![CDATA[Am. J. Phys.]]></source>
<year>1994</year>
<volume>62</volume>
<page-range>46</page-range></nlm-citation>
</ref>
<ref id="B8">
<label>8</label><nlm-citation citation-type="book">
<person-group person-group-type="author">
<name>
<surname><![CDATA[McDermott]]></surname>
<given-names><![CDATA[L.C.]]></given-names>
</name>
<name>
<surname><![CDATA[Shaffer]]></surname>
<given-names><![CDATA[P]]></given-names>
</name>
</person-group>
<collab>Physics Education Group at the University of Washington</collab>
<source><![CDATA[Tutorials in Introductory Physics]]></source>
<year>2002</year>
<publisher-loc><![CDATA[^eNew Jersey New Jersey]]></publisher-loc>
<publisher-name><![CDATA[Prentice-Hall]]></publisher-name>
</nlm-citation>
</ref>
<ref id="B9">
<label>9</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[O'Brien Pride]]></surname>
<given-names><![CDATA[T]]></given-names>
</name>
<name>
<surname><![CDATA[Vokos]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
<name>
<surname><![CDATA[McDermott]]></surname>
<given-names><![CDATA[L.C.]]></given-names>
</name>
</person-group>
<source><![CDATA[Am. J. of Phys.]]></source>
<year>1998</year>
<volume>66</volume>
<page-range>147</page-range></nlm-citation>
</ref>
<ref id="B10">
<label>10</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Kautz]]></surname>
<given-names><![CDATA[C.H.]]></given-names>
</name>
<name>
<surname><![CDATA[Heron]]></surname>
<given-names><![CDATA[P.R.L.]]></given-names>
</name>
<name>
<surname><![CDATA[Loverude]]></surname>
<given-names><![CDATA[M.E.]]></given-names>
</name>
<name>
<surname><![CDATA[McDermott]]></surname>
<given-names><![CDATA[L.C.]]></given-names>
</name>
</person-group>
<source><![CDATA[Am. J. of Phys.]]></source>
<year>2005</year>
<volume>73</volume>
<page-range>1055</page-range></nlm-citation>
</ref>
<ref id="B11">
<label>11</label><nlm-citation citation-type="journal">
<person-group person-group-type="author">
<name>
<surname><![CDATA[Flores]]></surname>
<given-names><![CDATA[S]]></given-names>
</name>
</person-group>
<source><![CDATA[CULCYT]]></source>
<year>2008</year>
<volume>5</volume>
<page-range>19</page-range></nlm-citation>
</ref>
</ref-list>
</back>
</article>
