Have done a simple magnet falling (under free fall) and how the magnetic field lines move along with it.<br /><br />In order to change the number of field lines, please edit the variable NField in the variables page.<br /><br /><br />Thank to Wolfgang Christian Magnetic Dipole Field 3D Model at http://www.opensourcephysics.org/document/ServeFile.cfm?ID=12361&amp;DocID=3083<br />I have modified the magnetic field line codes so that the magnetic field lines are drawn at the start and it is not drawn dynamically.<br /><br /><br />Please press the reset button if you can&#039;t see the magnetic field lines. <p><applet code='users.sgeducation.engrg1.FallingMagnetFieldLine_pkg.FallingMagnetFieldLineApplet.class' codebase='ejsuser/130498/' archive='ejs_FallingMagnetFieldLine.jar' name='FallingMagnetFieldLine9512' id='FallingMagnetFieldLine9512' width='600' height='600' mayscript=true><param name='draggable' value='true'></applet></p>/htdocs/ntnujava/ejsuser/130498/users/sgeducation/engrg1/FallingMagnetFieldLine_pkg/FallingMagnetFieldLine.properties<a href='htmltag.php?code=users.sgeducation.engrg1.FallingMagnetFieldLine_pkg.FallingMagnetFieldLineApplet.class&name=FallingMagnetFieldLine&muid=130498' target='_blank'>Full screen applet</a> or <font color="#FF0000">Problem viewing java?</font><a href="http://www.java.com/en/download/help/jcp_security.xml" target="trusted">Add http://www.phy.ntnu.edu.tw/ to exception site list</a><br><b>Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop.</b> This work is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by/2.5/tw/deed.en">Creative Commons Attribution 2.5 Taiwan License</a><br><a href='ntnujavazip.php?ejsuserjar=9512' title='ejs_FallingMagnetFieldLine.jar' target='userjar'>Download EJS jar file</a>(1008kB):double click downloaded file to run it. (8 times by 7 users) , <a href='ntnujavazip.php?ejsuserjar=9512&type=ejs' target='userjar'>Download EJS source</a> <a href='/demolab/phpBB/ejswui.php?ejsuser=ejsuser/130498/users/sgeducation/engrg1/FallingMagnetFieldLine.ejs' target='ejsxml'>View EJS source</a><img src='images/help.gif' onClick='showejsmsg(9512)'><img src='images/plus.gif' onClick='ejsparser(9512,"FallingMagnetFieldLine");'><div id='ejsmsg9512'></div>