{ "information": { "Title": "ejss_model_MagneticBarFieldsecondmagnet06 Ejs Open Source 2 Bar Magnets and Compass Model java applet", "Author": [ "lookang (weelookang@gmail.com) , Fu-Kwun Hwang, Wolfgang Chrisitan, Francisco Esquembre", "Fu-Kwun Hwang", "Wolfgang Chrisitan", "Francisco Esquembre", "Anne Cox", "tina" ], "AuthorLogo": [ "./01authorlookang50x50.png", "./01authorfu-kwun.hwang.png", "./01authorwc_icon.png", "./01authorPacoEsquembre2011.png", "./cox.png", "" ], "Password": "", "Keywords": "magnetic field, dipole, bar magnet, 2 bar magnets", "Abstract": "e-mail: fem@um.es\nremixed by lookang here weelookang@gmail.com\nhttp://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1602\nEjs Open Source 2 Bar Magnets & Compass Model java applet\nhttp://weelookang.blogspot.sg/2010/06/ejs-open-source-2-bar-magnets-compass.html ", "Copyright": "CC-BY-SA-NC", "Level": "introductory", "Language": "english", "Logo": [ "./Bar_magnet_and_compass_2/2016-05-31_1605s.png" ], "RunAlways": "true", "ModelTab": "", "ModelTabTitle": "", "ModelName": "", "FixedNavigationBar": "false", "CSSFile": "", "DetectedFiles": [ "./01authorPacoEsquembre2011.png", "./01authorfu-kwun.hwang.png", "./01authorlookang50x50.png", "./01authorwc_icon.png", "./Bar_magnet_and_compass_2/2016-05-31_1605s.png", "./MagneticBarField/TwoBarMagnetsandCompass.html", "./MagneticBarField/barMagnetField.jpg", "./cox.png" ], "AuxiliaryFiles": [ "./Bar_magnet_and_compass_2/" ], "HTMLHead": "\n\n\n\n", "SaveInXMLFormat": "false", "IncludeSource": "true", "IncludeLibrary": "true", "UglifyJS": "false", "PreviewFullModel": "false", "UseInterpreter": "true", "UseDeltaForODE": "false" }, "description": { "pages": [ { "Name": "Magnetic Bar Field", "Active": "true", "Internal": "false", "Type": "DESCRIPTION_EDITOR", "Locale": "_default_", "Title": "Magnetic Bar Field", "External": "true", "Code": "./MagneticBarField/TwoBarMagnetsandCompass.html" } ] }, "model": { "variables": { "pages": [ { "Name": "Field Vars", "Active": "true", "Internal": "false", "Type": "VARIABLE_EDITOR", "PageComment": "", "Variables": [ { "Name": "", "Value": "", "Type": "int", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "print", "Value": "false", "Type": "boolean", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "fontb", "Value": "\"normal bold 2vw \"", "Type": "String", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "font", "Value": "\"normal normal 2vw \"", "Type": "String", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "nd", "Value": "22", "Type": "int", "Dimension": "", "Comment": "number of dipoles", "Domain": "public" }, { "Name": "nd2", "Value": "nd+2", "Type": "int", "Dimension": "", "Comment": "unused", "Domain": "public" }, { "Name": "dx", "Value": "1.0/(nd-1)", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "dipoles", "Value": "0", "Type": "double", "Dimension": "[nd+2][2]", "Comment": "positions of dipoles so that are 11 on each horizontal row again for symmetry space out from -0.5 to 0.5 by lookang", "Domain": "public" }, { "Name": "dipolesearth", "Value": "0", "Type": "double", "Dimension": "[2][nd]", "Comment": "", "Domain": "public" }, { "Name": "fieldValue", "Value": "\"0\"", "Type": "String", "Dimension": "", "Comment": "magnitude of magnetic field reported by compass", "Domain": "public" }, { "Name": "fieldValueBx", "Value": "\"0\"", "Type": "String", "Dimension": "", "Comment": "added by lookang text value Bx resolve to axis of horizontal magnet", "Domain": "public" }, { "Name": "fieldValueBy", "Value": "\"0\"", "Type": "String", "Dimension": "", "Comment": "added by lookang text value By resolve to axis of horizontal magnet", "Domain": "public" }, { "Name": "fieldValueBx1", "Value": "\"\"", "Type": "String", "Dimension": "", "Comment": "added by lookang text value Bx resolve to universal x", "Domain": "public" }, { "Name": "fieldValueBy1", "Value": "\"\"", "Type": "String", "Dimension": "", "Comment": "added by lookang text value Bx resolve to universal y", "Domain": "public" }, { "Name": "fieldValueAngle", "Value": "\"0\"", "Type": "String", "Dimension": "", "Comment": "added by lookang text value Angle", "Domain": "public" }, { "Name": "angledeg", "Value": "", "Type": "double", "Dimension": "", "Comment": "added by lookang text value Angle in degree calculation in double.", "Domain": "public" }, { "Name": "angledeg1", "Value": "0", "Type": "double", "Dimension": "", "Comment": "universal angle after adding rotation cta", "Domain": "public" }, { "Name": "fieldValueAngledeg", "Value": "\"0\"", "Type": "String", "Dimension": "", "Comment": "added by lookang text value Angle in degree in string TT NOT USED", "Domain": "public" }, { "Name": "fieldValueAngledeg1", "Value": "\"\"", "Type": "String", "Dimension": "", "Comment": "universal angle after adding rotation cta", "Domain": "public" }, { "Name": "m", "Value": "0.05", "Type": "double", "Dimension": "", "Comment": "magnetic dipole moment", "Domain": "public" }, { "Name": "xmax", "Value": "1.5", "Type": "double", "Dimension": "", "Comment": "panel size", "Domain": "public" }, { "Name": "ymax", "Value": "1", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "nx", "Value": "41", "Type": "int", "Dimension": "", "Comment": "number of field vectors in x-direction change to 21 from 20 for symmetrically field vector by lookang", "Domain": "public" }, { "Name": "ny", "Value": "41", "Type": "int", "Dimension": "", "Comment": "number of field vectors in y direction change to 21 from 20 for symmetrically field vector by lookang", "Domain": "public" }, { "Name": "B", "Value": "", "Type": "double", "Dimension": "[4]", "Comment": "B compute lookang", "Domain": "public" }, { "Name": "xField", "Value": "0", "Type": "double", "Dimension": "[nx][ny]", "Comment": "magnetic field x-component", "Domain": "public" }, { "Name": "yField", "Value": "0", "Type": "double", "Dimension": "[nx][ny]", "Comment": "magnetic field y-component", "Domain": "public" }, { "Name": "magField", "Value": "0", "Type": "double", "Dimension": "[nx][ny]", "Comment": "magnetic field magnitude", "Domain": "public" }, { "Name": "negativexField", "Value": "0", "Type": "double", "Dimension": "[nx][ny]", "Comment": "", "Domain": "public" }, { "Name": "negativeyField", "Value": "0", "Type": "double", "Dimension": "[nx][ny]", "Comment": "", "Domain": "public" }, { "Name": "R", "Value": "2", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" } ] }, { "Name": "Display Vars", "Active": "true", "Internal": "false", "Type": "VARIABLE_EDITOR", "PageComment": "", "Variables": [ { "Name": "direction", "Value": "0", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "netForce", "Value": "0", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "massMagnet", "Value": "1", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "vxMagnet", "Value": "0", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "xMagnet", "Value": "0", "Type": "double", "Dimension": "", "Comment": "x position of magnet", "Domain": "public" }, { "Name": "yMagnet", "Value": "0", "Type": "double", "Dimension": "", "Comment": "y position of magnet", "Domain": "public" }, { "Name": "xMagnetDrag", "Value": "yMagnet+1", "Type": "double", "Dimension": "", "Comment": "x position of magnet", "Domain": "public" }, { "Name": "yMagnetDrag", "Value": "yMagnet", "Type": "double", "Dimension": "", "Comment": "y position of magnet", "Domain": "public" }, { "Name": "xMagnettransform", "Value": "0", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "yMagnettransform", "Value": "0", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "store", "Value": "41", "Type": "int", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "counter", "Value": "0", "Type": "int", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "xCompass", "Value": "0.7", "Type": "double", "Dimension": "", "Comment": "x position of compass", "Domain": "public" }, { "Name": "xCompassstore", "Value": "-xmax-1", "Type": "double", "Dimension": "[store]", "Comment": "x position of compass", "Domain": "public" }, { "Name": "yCompass", "Value": "0.01501501501501501", "Type": "double", "Dimension": "", "Comment": "y position of compass", "Domain": "public" }, { "Name": "yCompassstore", "Value": "-ymax-1", "Type": "double", "Dimension": "[store]", "Comment": "y position of compass", "Domain": "public" }, { "Name": "xCompasstransform", "Value": "0", "Type": "double", "Dimension": "", "Comment": "transform xCompass to new coordinate system after angle cta", "Domain": "public" }, { "Name": "yCompasstransform", "Value": "0", "Type": "double", "Dimension": "", "Comment": "transform yCompass to new coordinate system after angle cta", "Domain": "public" }, { "Name": "xCompasstransform1", "Value": "0", "Type": "double", "Dimension": "", "Comment": "transform back to universal coordinate system after angle -cta", "Domain": "public" }, { "Name": "yCompasstransform1", "Value": "0", "Type": "double", "Dimension": "", "Comment": "transform back to universal coordinate system after angle -cta", "Domain": "public" }, { "Name": "Magnetsizex", "Value": "1.12", "Type": "double", "Dimension": "", "Comment": "Magnetsizex added by lookang", "Domain": "public" }, { "Name": "Magnetsizey", "Value": "0.22", "Type": "double", "Dimension": "", "Comment": "Magnetsizey added by lookang", "Domain": "public" }, { "Name": "equilibriumTheta", "Value": "0", "Type": "double", "Dimension": "", "Comment": "angular orientation of compass at equilibrium", "Domain": "public" }, { "Name": "hideField", "Value": "false", "Type": "boolean", "Dimension": "", "Comment": "whether to hide magnet and field vectors", "Domain": "public" }, { "Name": "randomMagnetLocation", "Value": "false", "Type": "boolean", "Dimension": "", "Comment": "if magnet will be moved to a random position", "Domain": "public" }, { "Name": "vectorfieldmax", "Value": "0", "Type": "double", "Dimension": "", "Comment": "for varying the magnetic field display", "Domain": "public" }, { "Name": "vectorfieldmaxopposite", "Value": "100", "Type": "double", "Dimension": "", "Comment": "for varying the magnetic field display from 10 to 100", "Domain": "public" }, { "Name": "insidemagnet", "Value": "", "Type": "boolean", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "magnetNS", "Value": "false", "Type": "boolean", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "flipmagnet", "Value": "", "Type": "boolean", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "showCompass", "Value": "", "Type": "boolean", "Dimension": "", "Comment": "for varying the magnetic field display from 10 to 100", "Domain": "public" }, { "Name": "test", "Value": "", "Type": "boolean", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "", "Value": "", "Type": "boolean", "Dimension": "", "Comment": "", "Domain": "public" } ] }, { "Name": "ODE Vars", "Active": "true", "Internal": "false", "Type": "VARIABLE_EDITOR", "PageComment": "ODE variables for compass", "Variables": [ { "Name": "k", "Value": "1", "Type": "double", "Dimension": "", "Comment": "Hooke's law restoring force", "Domain": "public" }, { "Name": "damp", "Value": "2", "Type": "double", "Dimension": "", "Comment": "damping constant change from b to aviod confusion", "Domain": "public" }, { "Name": "theta", "Value": "0", "Type": "double", "Dimension": "", "Comment": "angular orientation of compass needle", "Domain": "public" }, { "Name": "thetastore", "Value": "0", "Type": "double", "Dimension": "[store]", "Comment": "angular orientation of compass needle", "Domain": "public" }, { "Name": "deltaTheta", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "deltaThetastore", "Value": "", "Type": "double", "Dimension": "[store]", "Comment": "", "Domain": "public" }, { "Name": "omega", "Value": "0", "Type": "double", "Dimension": "", "Comment": "angular velocity of compass needle", "Domain": "public" }, { "Name": "omegastore", "Value": "0", "Type": "double", "Dimension": "[store]", "Comment": "angular velocity of compass needle", "Domain": "public" }, { "Name": "t", "Value": "0", "Type": "double", "Dimension": "", "Comment": "time", "Domain": "public" }, { "Name": "dt", "Value": "0.1", "Type": "double", "Dimension": "", "Comment": "time increment", "Domain": "public" }, { "Name": "pi", "Value": "Math.PI", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" } ] }, { "Name": "earth", "Active": "true", "Internal": "false", "Type": "VARIABLE_EDITOR", "PageComment": "", "Variables": [ { "Name": "earth", "Value": "false", "Type": "boolean", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "cta", "Value": "0", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "cs", "Value": "Math.cos(cta)", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "sc", "Value": "Math.sin(cta)", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "cs1", "Value": "Math.cos(-cta)", "Type": "double", "Dimension": "", "Comment": "needed for rotation backwards bt -cta", "Domain": "public" }, { "Name": "sc1", "Value": "Math.sin(-cta)", "Type": "double", "Dimension": "", "Comment": "needed for rotation backwards bt -cta", "Domain": "public" }, { "Name": "ca", "Value": "0", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "a2c", "Value": "pi/180", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "", "Value": "", "Type": "boolean", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" } ] }, { "Name": "2ndmagnet", "Active": "true", "Internal": "false", "Type": "VARIABLE_EDITOR", "PageComment": "", "Variables": [ { "Name": "magnet1", "Value": "true", "Type": "boolean", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "magnet2", "Value": "false", "Type": "boolean", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "dipoles2", "Value": "0", "Type": "double", "Dimension": "[nd+2][2]", "Comment": "unused", "Domain": "public" }, { "Name": "massMagnet2", "Value": "1", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "vxMagnet2", "Value": "0", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "xMagnet2", "Value": "0.6532091097308488", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "yMagnet2", "Value": "-0.07660455486542439", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "xMagnet2Drag", "Value": "xMagnet2+0.7", "Type": "double", "Dimension": "", "Comment": "x position of magnet", "Domain": "public" }, { "Name": "yMagnet2Drag", "Value": "yMagnet2", "Type": "double", "Dimension": "", "Comment": "y position of magnet", "Domain": "public" }, { "Name": "Magnetsizex2", "Value": "1.12", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "Magnetsizey2", "Value": "0.22", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "cta2", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "ca2", "Value": "0", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "cs2", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "sc2", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "cs3", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "sc3", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "xMagnettransform2", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "yMagnettransform2", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "xCompasstransform2", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "yCompasstransform2", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "xCompasstransform3", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "yCompasstransform3", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "randomMagnetLocation2", "Value": "", "Type": "boolean", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "bf1", "Value": "0", "Type": "double", "Dimension": "[2]", "Comment": "", "Domain": "public" }, { "Name": "bf2", "Value": "0", "Type": "double", "Dimension": "[2]", "Comment": "", "Domain": "public" }, { "Name": "lcst", "Value": "1", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "rcst", "Value": "0", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "scale", "Value": "1", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "bxField", "Value": "0.0", "Type": "double", "Dimension": "", "Comment": "at compass location ", "Domain": "public" }, { "Name": "byField", "Value": "0.0", "Type": "double", "Dimension": "", "Comment": "at compass location by FKH", "Domain": "public" }, { "Name": "", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" } ] }, { "Name": "layout", "Active": "true", "Internal": "false", "Type": "VARIABLE_EDITOR", "PageComment": "", "Variables": [ { "Name": "", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "textt", "Value": "\"select the different position of RED and Blue dots and click play\"", "Type": "String", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "Width", "Value": "(_isEPub)?\"400\":\"100%\"", "Type": "String", "Dimension": "", "Comment": "display width", "Domain": "public" }, { "Name": "Height", "Value": "(_isEPub)?\"500\":\"100%\"", "Type": "String", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "Width1", "Value": "\"100%\"", "Type": "String", "Dimension": "", "Comment": "display width", "Domain": "public" }, { "Name": "Width2", "Value": "\"0%\"", "Type": "String", "Dimension": "", "Comment": "display width", "Domain": "public" }, { "Name": "Width3", "Value": "\"0%\"", "Type": "String", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "Width4", "Value": "\"0%\"", "Type": "String", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "Height1", "Value": "\"15\"", "Type": "String", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "graph", "Value": "true", "Type": "boolean", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "world", "Value": "true", "Type": "boolean", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "disabledworld", "Value": "false", "Type": "boolean", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "disabled", "Value": "false", "Type": "boolean", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "isAndroid", "Value": "checkAndroid()", "Type": "boolean", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "", "Value": "", "Type": "String", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "iOS", "Value": "/iPad|iPhone|iPod/.test(navigator.userAgent) && !window.MSStream", "Type": "boolean", "Dimension": "", "Comment": "http://stackoverflow.com/questions/9038625/detect-if-device-is-ios", "Domain": "public" }, { "Name": "iPad", "Value": "/iPad/.test(navigator.userAgent) && !window.MSStream", "Type": "boolean", "Dimension": "", "Comment": "http://stackoverflow.com/questions/9038625/detect-if-device-is-ios", "Domain": "public" }, { "Name": "iPhone", "Value": "/iPhone|iPod/.test(navigator.userAgent) && !window.MSStream", "Type": "boolean", "Dimension": "", "Comment": "http://stackoverflow.com/questions/9038625/detect-if-device-is-ios", "Domain": "public" }, { "Name": "Android", "Value": "/Android|android/i.test(navigator.userAgent)", "Type": "boolean", "Dimension": "", "Comment": "", "Domain": "public" } ] }, { "Name": "Fieldlines", "Active": "true", "Internal": "false", "Type": "VARIABLE_EDITOR", "PageComment": "", "Variables": [ { "Name": "inside", "Value": "\"\"", "Type": "String", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "selected", "Value": "\"magnet 1 on\"", "Type": "String", "Dimension": "[1]", "Comment": "", "Domain": "public" }, { "Name": "selected2", "Value": "\"magnet 2 on\"", "Type": "String", "Dimension": "[1]", "Comment": "", "Domain": "public" }, { "Name": "selected3", "Value": "\"one magnet point right\"", "Type": "String", "Dimension": "[1]", "Comment": "", "Domain": "public" }, { "Name": "vectorIndex", "Value": "0", "Type": "int", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "FieldFlag", "Value": "true", "Type": "boolean", "Dimension": "", "Comment": "toggle for overlaying streamline field lines", "Domain": "public" }, { "Name": "nVectors", "Value": "15", "Type": "int", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "nVectorsMax", "Value": "15", "Type": "int", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "nVectorsSq", "Value": "nVectors*nVectors", "Type": "int", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "Vectorx", "Value": "0.0", "Type": "double", "Dimension": "[nVectorsSq]", "Comment": "", "Domain": "public" }, { "Name": "Vectory", "Value": "0.0", "Type": "double", "Dimension": "[nVectorsSq]", "Comment": "", "Domain": "public" }, { "Name": "Fieldx", "Value": "0.000001", "Type": "double", "Dimension": "[nVectorsSq]", "Comment": "", "Domain": "public" }, { "Name": "Fieldy", "Value": "0.0", "Type": "double", "Dimension": "[nVectorsSq]", "Comment": "", "Domain": "public" }, { "Name": "BF1", "Value": "0.0", "Type": "double", "Dimension": "[2]", "Comment": "", "Domain": "public" }, { "Name": "BF2", "Value": "0.0", "Type": "double", "Dimension": "[2]", "Comment": "", "Domain": "public" }, { "Name": "posx", "Value": "0.0", "Type": "double", "Dimension": "[nVectorsSq]", "Comment": "", "Domain": "public" }, { "Name": "posy", "Value": "0.0", "Type": "double", "Dimension": "[nVectorsSq]", "Comment": "", "Domain": "public" }, { "Name": "textSetx", "Value": "\"\"", "Type": "String", "Dimension": "[nVectorsSq]", "Comment": "", "Domain": "public" }, { "Name": "textSety", "Value": "\"\"", "Type": "String", "Dimension": "[nVectorsSq]", "Comment": "", "Domain": "public" }, { "Name": "textSetthetaField", "Value": "\"\"", "Type": "String", "Dimension": "[nVectorsSq]", "Comment": "", "Domain": "public" }, { "Name": "thetaField", "Value": "0", "Type": "double", "Dimension": "[nVectorsSq]", "Comment": "", "Domain": "public" }, { "Name": "", "Value": "", "Type": "double", "Dimension": "", "Comment": "", "Domain": "public" }, { "Name": "nFieldLineSegmentsMax", "Value": "480", "Type": "int", "Dimension": "", "Comment": "maximum number of short segments used to draw field-line overlays", "Domain": "public" }, { "Name": "fieldLineCount", "Value": "0", "Type": "int", "Dimension": "", "Comment": "current number of visible streamline segments", "Domain": "public" }, { "Name": "fieldLineX", "Value": "0.0", "Type": "double", "Dimension": "[nFieldLineSegmentsMax]", "Comment": "x positions for streamline segment centers", "Domain": "public" }, { "Name": "fieldLineY", "Value": "0.0", "Type": "double", "Dimension": "[nFieldLineSegmentsMax]", "Comment": "y positions for streamline segment centers", "Domain": "public" }, { "Name": "fieldLineTheta", "Value": "0.0", "Type": "double", "Dimension": "[nFieldLineSegmentsMax]", "Comment": "segment orientations for streamline overlays", "Domain": "public" }, { "Name": "fieldLineStep", "Value": "0.06", "Type": "double", "Dimension": "", "Comment": "integration step length for streamline tracing", "Domain": "public" }, { "Name": "fieldLineSegmentLength", "Value": "0.05", "Type": "double", "Dimension": "", "Comment": "display length for each streamline segment", "Domain": "public" }, { "Name": "fieldLineMaxSteps", "Value": "20", "Type": "int", "Dimension": "", "Comment": "maximum number of segments traced from each seed point", "Domain": "public" }, { "Name": "fieldLineMargin", "Value": "0.08", "Type": "double", "Dimension": "", "Comment": "extra distance used for starting seeds and clipping bounds", "Domain": "public" } ] } ] }, "initialization": { "pages": [ { "Name": "Init Page", "Active": "true", "Internal": "false", "Type": "CODE_EDITOR", "Comment": "", "Code": "// spacing done by lookang to achieve perfectly symmetry of B\n// need nd =22 because from x =-0.5 to 0.5 put 11 each row\n// 2 rows so nd = 11*2 =22\n\nvar dx=1.0/(nd-2); //set up dipoles under bar magnet\nfor(var i=0; i<=(nd-1); i++) {\n dipoles[i][0]=-0.5+i*dx; // x position of first line of dipoles bottom\n dipoles[i][1]=-0.04; // y position move down by -0.04 of first line of dipoles bottom\n dipoles[i+1][0]=-0.5+i*dx; // x position of 2nd line of dipoles top\n dipoles[i+1][1]=0.04; // y position move up by +0.04 of top line of dipoles bottom\n i++;\n}\n\n//magnet1=true;\n//magnet2=true;\ncomputeField();\n\n\n\n" }, { "Name": "Init Page 2", "Active": "true", "Internal": "false", "Type": "CODE_EDITOR", "Comment": "", "Code": "for (var i = 0; i < nVectors; i++)\n{\n for (var j = 0; j < nVectors; j++)\n {\n vectorIndex = i+nVectors*j;\n \n Vectorx[vectorIndex] = -xmax*scale+i/5;\n Vectory[vectorIndex] = -ymax*scale+j/5;\n posx[vectorIndex]=Vectorx[vectorIndex]-0.5*Fieldx[vectorIndex];\n posy[vectorIndex]=Vectory[vectorIndex]-0.5*Fieldy[vectorIndex];\n }\n}" }, { "Name": "laytwo magnets", "Active": "true", "Internal": "false", "Type": "CODE_EDITOR", "Comment": "", "Code": "xMagnet = -1;\nyMagnet = 0;\nxMagnet2 = 1-0.2;\nyMagnet2 = 0;\nselected[0]=\"\u03b8\u2081 =0\u00b0\";\nselected2[0]=\"\u03b8\u2082 =0\u00b0\";\nca = 0;\n cta=ca*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\n//\nca2 = -0;\n cta=ca2*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\nmagnet1=true;\n if(magnet1)lcst=1;\nelse lcst=0;\n//computeField ();\n\nmagnet2=true;\n if(magnet2)rcst=1;\nelse rcst=0;\ncomputeField ();\n\n\nxMagnetDrag = xMagnet+0.7; //force rotate unicode to follow magnet\nyMagnetDrag = yMagnet;\nxMagnet2Drag = xMagnet2+0.7; //force rotate unicode to follow magnet\nyMagnet2Drag = yMagnet2;\n\n" } ] }, "evolution": { "information": { "FPS": "25", "SPD": "1", "RealTimeVariable": "", "Autoplay": "true" }, "pages": [ { "Name": "Evol Page", "Active": "true", "Internal": "false", "Type": "ODE_EDITOR", "Comment": "", "IndependentVariable": "t", "Increment": "dt", "Equations": [ { "state": "theta", "rate": "omega" }, { "state": "omega", "rate": "-k*Math.sqrt(bxField*bxField+byField*byField)*(Math.sin(deltaTheta))-damp*omega" }, { "state": "xMagnet", "rate": "vxMagnet" }, { "state": "xMagnet2", "rate": "vxMagnet2" }, { "state": "vxMagnet", "rate": "netForce/(massMagnet)" }, { "state": "vxMagnet2", "rate": "netForce/(massMagnet2)" }, { "state": "", "rate": "" } ], "Method": "RungeKuttaFehlberg", "AbsoluteTolerance": "0.00001", "PreliminaryCode": { "Code": "var deltaTheta=theta-equilibriumTheta;\n", "Comment": "Code to be executed before rate equations are evaluated" }, "EventMaximumStep": "", "Events": { "pages": [] }, "ZenoEffect": { "Code": "", "Comment": "", "StopAfterEffect": "true" }, "AccelerationIndependentOfVelocity": "false", "ForceSynchronization": "false", "UseBestInterpolation": "false", "EstimateFirstStep": "false", "MemoryLength": "", "InternalStep": "", "MaximumStep": "", "MaximumNumberOfSteps": "10000", "RelativeTolerance": "", "DelayList": "", "DelayMaximum": "", "DelayAddDiscont": "", "DelayInitialCondition": { "Code": "", "Comment": "" }, "DirectIncidenceMatrix": "", "Discontinuities": { "pages": [] }, "ErrorHandling": { "pages": [ { "Type": "ERROR_EDITOR", "Name": "Error handling code", "Active": "true", "Internal": "false", "Code": "", "Comment": "", "ErrorType": "ANY_ERROR" } ] } } ] }, "fixed_relations": { "pages": [ { "Name": "FixRel Page 2", "Active": "true", "Internal": "false", "Type": "CODE_EDITOR", "Comment": "", "Code": "cta = ca*a2c; // use to allow slider ca to control cta \ncs=Math.cos(cta);//FKH\nsc=Math.sin(cta);//FKH\ncs1=Math.cos(-cta); // use to rotate from magnet axes to universal axes\nsc1=Math.sin(-cta); // use to rotate from magnet axes to universal axes\n\n// required for compass in magnet to work to 255 \nxMagnettransform = xMagnet*cs+yMagnet*sc; // transform to magnet axes\nyMagnettransform = -xMagnet*sc+yMagnet*cs; // transform to magnet axes\nxCompasstransform = xCompass*cs+yCompass*sc; // transform to magnet axes\nyCompasstransform = -xCompass*sc+yCompass*cs; // transform to magnet axes\nxCompasstransform1 = xCompasstransform*cs1+yCompasstransform*sc1; // transform to universal axes\nyCompasstransform1 = -xCompasstransform*sc1+yCompasstransform*cs1; // transform to universal axes\n\n\n// for 2nd magnet\ncta2 = ca2*a2c; // use to allow slider ca to control cta \ncs2=Math.cos(cta2);//FKH\nsc2=Math.sin(cta2);//FKH\ncs3=Math.cos(-cta2); // use to rotate from magnet axes to universal axes\nsc3=Math.sin(-cta2); // use to rotate from magnet axes to universal axes\nxMagnettransform2 = xMagnet2*cs2+yMagnet2*sc2; // transform to magnet axes\nyMagnettransform2 = -xMagnet2*sc2+yMagnet2*cs2; // transform to magnet axes\nxCompasstransform2 = xCompass*cs2+yCompass*sc2; // transform to magnet axes\nyCompasstransform2 = -xCompass*sc2+yCompass*cs2; // transform to magnet axes\nxCompasstransform3 = xCompasstransform2*cs3+yCompasstransform2*sc3; // transform to universal axes\nyCompasstransform3 = -xCompasstransform2*sc3+yCompasstransform2*cs3; \n\n\nbf1=getB((xCompass-xMagnet)*cs+(yCompass-yMagnet)*sc,-(xCompass-xMagnet)*sc+(yCompass-yMagnet)*cs);//FKH\nbf2=getB((xCompass-xMagnet2)*cs2+(yCompass-yMagnet2)*sc2,-(xCompass-xMagnet2)*sc2+(yCompass-yMagnet2)*cs2);//FKH\n\n//https://www.kirupa.com/forum/showthread.php?336745-Mathematically-check-if-a-point-is-inside-a-rotated-rectangle\n \nvar dx = xCompass-xMagnet;\nvar dy = yCompass-yMagnet;\nvar currA = Math.atan2(dy,dx);\nvar newA = currA - cta;\nvar h1 = Math.sqrt(dx*dx+dy*dy);\nvar x2 =Math.cos(newA) * h1;\nvar y2 = Math.sin(newA) * h1;\n\nvar dx2 = xCompass-xMagnet2;\nvar dy2 = yCompass-yMagnet2;\nvar currA2 = Math.atan2(dy2,dx2);\nvar newA2 = currA2 - cta2;\nvar h2 = Math.sqrt(dx2*dx2+dy2*dy2);\nvar x22 =Math.cos(newA2) * h2;\nvar y22 = Math.sin(newA2) * h2;\n\n //inside magnet1\n if (magnet1===true&&(x2 > - 0.5 * Magnetsizex && x2 < 0.5 * Magnetsizex && y2 > - 0.5 * Magnetsizey && y2 < 0.5 * Magnetsizey))\n// if (xCompass<(xMagnet+Magnetsizex/2) && xCompass>(xMagnet-(Magnetsizex/2)) && yCompass<(yMagnet+Magnetsizey/2) && yCompass>(yMagnet-Magnetsizey/2))\n{\ntheta= cta;\nfieldValue=\"B= 225 T\";\nfieldValueBx1=\"Bx= \" +_view._format(225*Math.cos(theta),\"0.\")+ \" T\"; \nfieldValueBy1=\"By= \"+_view._format(225*Math.sin(theta),\"0.\")+ \" T\";\nfieldValueAngledeg1 = theta*180/pi;\n}\n\n\n //inside magnet2\n else if (magnet2===true&&(x22 > - 0.5 * Magnetsizex2 && x22 < 0.5 * Magnetsizex2 && y22 > - 0.5 * Magnetsizey2 && y22 < 0.5 * Magnetsizey2))\n// if (xCompass<(xMagnet+Magnetsizex/2) && xCompass>(xMagnet-(Magnetsizex/2)) && yCompass<(yMagnet+Magnetsizey/2) && yCompass>(yMagnet-Magnetsizey/2))\n{\ntheta= cta2;\nfieldValue=\"B= 225 T\";\nfieldValueBx1=\"Bx= \" +_view._format(225*Math.cos(theta),\"0.\")+ \" T\"; \nfieldValueBy1=\"By= \"+_view._format(225*Math.sin(theta),\"0.\")+ \" T\";\nfieldValueAngledeg1 = theta*180/pi;\n}\n \nelse{ // catch all\nbxField = lcst*(bf1[0]*cs-bf1[1]*sc)+rcst*(bf2[0]*cs2-bf2[1]*sc2);//FKH\n byField = lcst*(bf1[0]*sc+bf1[1]*cs)+rcst*(bf2[0]*sc2+bf2[1]*cs2);//FKH\nequilibriumTheta=Math.atan2(byField,bxField);//b[3];\nfieldValue=\"B=\"+_view._format(Math.sqrt(bxField*bxField+byField*byField),\"0.0\")+ \" T\";\n\n\n// display as x and y\nfieldValueBx1=\"Bx= \" +_view._format(bxField,\"0.0\")+ \" T\"; \nfieldValueBy1=\"By= \"+_view._format(byField,\"0.0\")+ \" T\";\n\n// new angle after rotate cta of magnet with universal x and y\nangledeg1 = Math.atan2(byField,bxField)*180/Math.PI;\nfieldValueAngledeg1 = \"\u03b8 = \"+ _view._format(angledeg1,\"0.0\") + \"\u00b0\";\n\n\nif(omega>0)omega=Math.min(omega,Math.PI); // keeps compass from spinning wildly\nelse omega=Math.max(omega,-Math.PI);\n\n\n// to make the strength slider 0 min and 100 max by weelk\nvectorfieldmax=100-vectorfieldmaxopposite;\n\n//\n//cs= Math.cos(cta);\n//sc=Math.sin(cta);\n//cta = ca*a2c;\n\n// prelim code moved to fix\ndeltaTheta=theta-equilibriumTheta;\n\n}" }, { "Name": "fieldlines", "Active": "true", "Internal": "false", "Type": "CODE_EDITOR", "Comment": "", "Code": "// Field for the vectors\nfor (i = 0; i < nVectors; i++)\n{\n for (j = 0; j < nVectors; j++)\n {\n vectorIndex = i+nVectors*j;\n// bf1=getB((xCompass-xMagnet)*cs+(yCompass-yMagnet)*sc,-(xCompass-xMagnet)*sc+(yCompass-yMagnet)*cs);//FKH\n//bf2=getB((xCompass-xMagnet2)*cs2+(yCompass-yMagnet2)*sc2,-(xCompass-xMagnet2)*sc2+(yCompass-yMagnet2)*cs2);//FKH\n\n BF1 = getBcomputeField((posx[vectorIndex]-xMagnet)*cs+(posy[vectorIndex]-yMagnet)*sc,-(posx[vectorIndex]-xMagnet)*sc+(posy[vectorIndex]-yMagnet)*cs);//FKH;\n BF2 =getBcomputeField((posx[vectorIndex]-xMagnet2)*cs2+(posy[vectorIndex]-yMagnet2)*sc2,-(posx[vectorIndex]-xMagnet2)*sc2+(posy[vectorIndex]-yMagnet2)*cs2);//FKH\n Fieldx[vectorIndex] = lcst*(BF1[0]*cs-BF1[1]*sc)+rcst*(BF2[0]*cs2-BF2[1]*sc2);//FKH\n Fieldy[vectorIndex] = lcst*(BF1[0]*sc+BF1[1]*cs)+rcst*(BF2[0]*sc2+BF2[1]*cs2);//FKH\n thetaField[vectorIndex]= Math.atan2(Fieldy[vectorIndex],Fieldx[vectorIndex]+0.00000001); //need a small amount to force answers to be correct\n //https://www.kirupa.com/forum/showthread.php?336745-Mathematically-check-if-a-point-is-inside-a-rotated-rectangle\n \nvar dx = posx[vectorIndex]-xMagnet;\nvar dy = posy[vectorIndex]-yMagnet;\nvar currA = Math.atan2(dy,dx);\nvar newA = currA - cta;\nvar h1 = Math.sqrt(dx*dx+dy*dy);\nvar x2 =Math.cos(newA) * h1;\nvar y2 = Math.sin(newA) * h1;\n //inside magnet1\n if (magnet1===true&&(x2 > - 0.5 * Magnetsizex && x2 < 0.5 * Magnetsizex && y2 > - 0.5 * Magnetsizey && y2 < 0.5 * Magnetsizey))\n// if (posx[vectorIndex]<(xMagnet+Magnetsizex/2) && posx[vectorIndex]>(xMagnet-(Magnetsizex/2)) && posy[vectorIndex]<(yMagnet+Magnetsizey/2) && posy[vectorIndex]>(yMagnet-Magnetsizey/2))\n{\nthetaField[vectorIndex]= cta;\n}\nvar dx2 = posx[vectorIndex]-xMagnet2;\nvar dy2 = posy[vectorIndex]-yMagnet2;\nvar currA2 = Math.atan2(dy2,dx2);\nvar newA2 = currA2 - cta2;\nvar h2 = Math.sqrt(dx2*dx2+dy2*dy2);\nvar x22 =Math.cos(newA2) * h2;\nvar y22 = Math.sin(newA2) * h2;\n //inside magnet2\n if (magnet2===true&&(x22 > - 0.5 * Magnetsizex2 && x22 < 0.5 * Magnetsizex2 && y22 > - 0.5 * Magnetsizey2 && y22 < 0.5 * Magnetsizey2))\n// if (posx[vectorIndex]<(xMagnet+Magnetsizex/2) && posx[vectorIndex]>(xMagnet-(Magnetsizex/2)) && posy[vectorIndex]<(yMagnet+Magnetsizey/2) && posy[vectorIndex]>(yMagnet-Magnetsizey/2))\n{\nthetaField[vectorIndex]= cta2;\n}\n\n\n textSetx[vectorIndex] = \"Fieldx\"+[vectorIndex]+\"=\"+_view._format(Fieldx[vectorIndex],\"0.00\");\n textSety[vectorIndex] = \"Fieldy\"+[vectorIndex]+\"=\"+_view._format(Fieldy[vectorIndex],\"0.00\");\n // inside[vectorIndex] =\"0\";\n textSetthetaField[vectorIndex] = [vectorIndex]+\"=\"+_view._format(thetaField[vectorIndex],\"0.00\");\n \n }\n}\n\nupdateFieldLineOverlay();\n" } ] }, "custom": { "pages": [ { "Name": "ComputeField2magnets", "Active": "true", "Internal": "false", "Type": "LIBRARY_EDITOR", "Comment": "", "Code": "//20151110 TT: note that the x and y are commented at this moment because \n// there is not vectorField2d equivalent object in EJSS\n// to be uncommented once such object is made available in future versions of EJSS.\n\nfunction computeField () {\n var x, y;\n for (var i=0; iMath.abs(muStatic*weightY)) { // sliding condition\n direction=(weightX+springForce+m>0)?-1:1; // true: right +, false -\n frictionForce=Math.sign(cartVx)*muKinetic*weightY; // replace v\n\n } \n \n \n else {\n frictionForce=-weightX-springForce;\n direction=0; // static friction\n \n }\n \n}\n\n" }, { "Name": "GetBComputeField", "Active": "true", "Internal": "false", "Type": "LIBRARY_EDITOR", "Comment": "", "Code": "// computes magnetic field components and magnitude from dipoles\n// rename this getB to getBcomputeField because need to separate the calculation of Field from Compass\nfunction getBcomputeField(xm, ym) {\n var b=[0,0]; //In JS you don't need to initialize the length of the array. It grows dynamically. \n var dx,dy,r2,r,r3,cos,sin;\n \n for(var i=0; i<=nd; i++) { // lookang change i -0.5*sx && xLocal < 0.5*sx && yLocal > -0.5*sy && yLocal < 0.5*sy;\n}\n\nfunction pointInsideAnyMagnet(px, py) {\n return (magnet1 && pointInsideRotatedMagnet(px, py, xMagnet, yMagnet, cta, Magnetsizex, Magnetsizey)) ||\n (magnet2 && pointInsideRotatedMagnet(px, py, xMagnet2, yMagnet2, cta2, Magnetsizex2, Magnetsizey2));\n}\n\nfunction getNetFieldAtPoint(px, py) {\n var left = getBcomputeField((px-xMagnet)*cs+(py-yMagnet)*sc,-(px-xMagnet)*sc+(py-yMagnet)*cs);\n var right = getBcomputeField((px-xMagnet2)*cs2+(py-yMagnet2)*sc2,-(px-xMagnet2)*sc2+(py-yMagnet2)*cs2);\n return [\n lcst*(left[0]*cs-left[1]*sc)+rcst*(right[0]*cs2-right[1]*sc2),\n lcst*(left[0]*sc+left[1]*cs)+rcst*(right[0]*sc2+right[1]*cs2)\n ];\n}\n\nfunction traceFieldLineFromSeed(startX, startY, directionSign) {\n var x = startX;\n var y = startY;\n for (var step = 0; step < fieldLineMaxSteps && fieldLineCount < nFieldLineSegmentsMax; step++) {\n if (Math.abs(x) > xmax*scale + fieldLineMargin || Math.abs(y) > ymax*scale + fieldLineMargin) break;\n if (pointInsideAnyMagnet(x, y) && step > 0) break;\n var field = getNetFieldAtPoint(x, y);\n var bx = field[0];\n var by = field[1];\n var mag = Math.sqrt(bx*bx + by*by);\n if (!isFinite(mag) || mag < 1.0e-6) break;\n var stepX = directionSign * fieldLineStep * bx / mag;\n var stepY = directionSign * fieldLineStep * by / mag;\n var nextX = x + stepX;\n var nextY = y + stepY;\n if (!isFinite(nextX) || !isFinite(nextY)) break;\n if (Math.abs(nextX) > xmax*scale + fieldLineMargin || Math.abs(nextY) > ymax*scale + fieldLineMargin) break;\n if (pointInsideAnyMagnet(nextX, nextY)) break;\n fieldLineX[fieldLineCount] = 0.5*(x+nextX);\n fieldLineY[fieldLineCount] = 0.5*(y+nextY);\n fieldLineTheta[fieldLineCount] = Math.atan2(stepY, stepX);\n fieldLineCount++;\n x = nextX;\n y = nextY;\n }\n}\n\nfunction addFieldLineSeedsForMagnet(mx, my, angle, sx, sy) {\n var offsets = [-0.26*sy, 0, 0.26*sy];\n var lead = 0.5*sx + fieldLineMargin;\n var cosA = Math.cos(angle);\n var sinA = Math.sin(angle);\n for (var pole = -1; pole <= 1; pole += 2) {\n for (var k = 0; k < offsets.length; k++) {\n var localX = pole * lead;\n var localY = offsets[k];\n var worldX = mx + localX*cosA - localY*sinA;\n var worldY = my + localX*sinA + localY*cosA;\n traceFieldLineFromSeed(worldX, worldY, 1);\n traceFieldLineFromSeed(worldX, worldY, -1);\n if (fieldLineCount >= nFieldLineSegmentsMax) return;\n }\n }\n}\n\nfunction updateFieldLineOverlay() {\n fieldLineCount = 0;\n if (!FieldFlag) return;\n if (magnet1) addFieldLineSeedsForMagnet(xMagnet, yMagnet, cta, Magnetsizex, Magnetsizey);\n if (magnet2) addFieldLineSeedsForMagnet(xMagnet2, yMagnet2, cta2, Magnetsizex2, Magnetsizey2);\n}" }, { "Name": "GetBvalueCompass", "Active": "true", "Internal": "false", "Type": "LIBRARY_EDITOR", "Comment": "", "Code": "// computes magnetic field components and magnitude from dipoles\n// rename this getB to getBcomputeField because need to separate the calculation of Field from Compass\nfunction getB(xm, ym) {\n var b=[0,0]; //In JS you don't need to initialize the length of the array. It grows dynamically.\n var dx,dy,r2,r,r3,cos,sin;\n for(var i=0; i<=nd; i++) { // lookang change i -1; //&& ua.indexOf(\"mobile\");\n}" } ] }, "elements": { "list": [] } }, "view": { "Tree": [ { "Name": "fullscreen", "Type": "Panel", "Expanded": "true", "Properties": [ { "name": "Width", "value": "Width" } ], "Children": [ { "Name": "controlPanel", "Type": "Panel", "Expanded": "true", "Properties": [ { "name": "Width", "value": "\"100%\"" }, { "name": "Font", "value": "font" }, { "name": "Display", "value": "print?\"none\":\"inline-flex\"" } ], "Children": [ { "Name": "comboBox", "Type": "ComboBox", "Properties": [ { "name": "Options", "value": "[\"NS unlike pole magnets LR\",\"SN unlike pole magnets LR\",\"two magnets point up\",\"NN like pole magnets LR\",\"SS like pole magnets LR\",\"two magnets point down\",\"compass show\",\"compass off\",\"user_defined\"]" }, { "name": "Tooltip", "value": "\"select user_defined and drag the mass\"" }, { "name": "OnChange", "value": "var option = _view.comboBox.getProperty(\"SelectedOptions\");\n//alert(option);\n\nif ( option==\"user_defined\"){\n \n }\n\n\nelse if ( option==\"one magnet point right\"){\nxMagnet = 0;\nyMagnet = 0;\nselected[0]=\"\u03b8\u2081 =0\u00b0\";\nca = 0;\n cta=ca*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\n//\nmagnet1=true;\n if(magnet1)lcst=1;\nelse lcst=0;\n//computeField ();\nselected2[0]=\"magnet 2 off\";\nmagnet2=false;\n if(magnet2)rcst=1;\nelse rcst=0;\ncomputeField ();\n }\n else if ( option==\"one magnet point up\"){\nxMagnet = 0;\nyMagnet = 0;\nselected[0]=\"\u03b8\u2081 =90\u00b0\";\nca = 90;\n cta=ca*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\n//\nmagnet1=true;\n if(magnet1)lcst=1;\nelse lcst=0;\n//computeField ();\nselected2[0]=\"magnet 2 off\";\nmagnet2=false;\n if(magnet2)rcst=1;\nelse rcst=0;\ncomputeField ();\n }\n\nelse if ( option==\"one magnet point left\"){\nxMagnet = 0;\nyMagnet = 0;\nselected[0]=\"\u03b8\u2081 =180\u00b0\";\nca = 180;\n cta=ca*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\n//\nmagnet1=true;\n if(magnet1)lcst=1;\nelse lcst=0;\n//computeField ();\nselected2[0]=\"magnet 2 off\";\nmagnet2=false;\n if(magnet2)rcst=1;\nelse rcst=0;\ncomputeField ();\n }\n\nelse if ( option==\"one magnet point down\"){\nxMagnet = 0;\nyMagnet = 0;\nselected[0]=\"\u03b8\u2081 =-90\u00b0\";\nca = -90;\n cta=ca*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\n//\nmagnet1=true;\n if(magnet1)lcst=1;\nelse lcst=0;\n//computeField ();\nselected2[0]=\"magnet 2 off\";\nmagnet2=false;\n if(magnet2)rcst=1;\nelse rcst=0;\ncomputeField ();\n }\n\n\nelse if ( option==\"NS unlike pole magnets LR\"){\nxMagnet = -1;\nyMagnet = 0;\nxMagnet2 = 1-0.2;\nyMagnet2 = 0;\nselected[0]=\"\u03b8\u2081 =0\u00b0\";\nselected2[0]=\"\u03b8\u2082 =0\u00b0\";\nca = 0;\n cta=ca*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\n//\nca2 = -0;\n cta=ca2*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\nmagnet1=true;\n if(magnet1)lcst=1;\nelse lcst=0;\n//computeField ();\n\nmagnet2=true;\n if(magnet2)rcst=1;\nelse rcst=0;\ncomputeField ();\n }\n //new\n else if ( option==\"SN unlike pole magnets LR\"){\nxMagnet = -1;\nyMagnet = 0;\nxMagnet2 = 1-0.2;\nyMagnet2 = 0;\nselected[0]=\"\u03b8\u2081 =180\u00b0\";\nselected2[0]=\"\u03b8\u2082 =180\u00b0\";\nca = 180;\n cta=ca*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\n//\nca2 = -180;\n cta=ca2*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\nmagnet1=true;\n if(magnet1)lcst=1;\nelse lcst=0;\n//computeField ();\n\nmagnet2=true;\n if(magnet2)rcst=1;\nelse rcst=0;\ncomputeField ();\n }\nelse if ( option==\"two magnets point up\"){\nxMagnet = -0.7;\nyMagnet = 0;\nxMagnet2 = 0.5;\nyMagnet2 = 0;\nselected[0]=\"\u03b8\u2081 =90\u00b0\";\nselected2[0]=\"\u03b8\u2082 =90\u00b0\";\nca = 90;\n cta=ca*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\n//\nca2 = 90;\n cta=ca2*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\nmagnet1=true;\n if(magnet1)lcst=1;\nelse lcst=0;\n//computeField ();\n\nmagnet2=true;\n if(magnet2)rcst=1;\nelse rcst=0;\ncomputeField ();\n }\n else if ( option==\"SS like pole magnets LR\"){\nxMagnet = -1;\nyMagnet = 0;\nxMagnet2 = 1-0.2;\nyMagnet2 = 0;\n\nselected[0]=\"\u03b8\u2081 =180\u00b0\";\nselected2[0]=\"\u03b8\u2082 =0\u00b0\";\nca = 180;\n cta=ca*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\n//\nca2 = 0;\n cta=ca2*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\nmagnet1=true;\n if(magnet1)lcst=1;\nelse lcst=0;\n//computeField ();\n\nmagnet2=true;\n if(magnet2)rcst=1;\nelse rcst=0;\ncomputeField ();\n }\n else if ( option==\"NN like pole magnets LR\"){\nxMagnet = -1;\nyMagnet = 0;\nxMagnet2 = 1-0.2;\nyMagnet2 = 0;\n\nselected[0]=\"\u03b8\u2081 =0\u00b0\";\nselected2[0]=\"\u03b8\u2082 =180\u00b0\";\nca = 0;\n cta=ca*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\n//\nca2 = 180;\n cta=ca2*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\nmagnet1=true;\n if(magnet1)lcst=1;\nelse lcst=0;\n//computeField ();\n\nmagnet2=true;\n if(magnet2)rcst=1;\nelse rcst=0;\ncomputeField ();\n }\n \n \nelse if ( option==\"two magnets point down\"){\nxMagnet = -0.7;\nyMagnet = 0;\nxMagnet2 = 0.5;\nyMagnet2 = 0;\nselected[0]=\"\u03b8\u2081 =-90\u00b0\";\nselected2[0]=\"\u03b8\u2082 =-90\u00b0\";\nca = -90;\n cta=ca*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\n//\nca2 = -90;\n cta=ca2*a2c;\ncs=Math.cos(cta);\nsc=Math.sin(cta);\nmagnet1=true;\n if(magnet1)lcst=1;\nelse lcst=0;\n//computeField ();\n\nmagnet2=true;\n if(magnet2)rcst=1;\nelse rcst=0;\ncomputeField ();\n }\nelse if ( option==\"compass show\"){\nshowCompass=true;\n_play();\n }\n else if ( option==\"compass off\"){\nshowCompass=false;\n }\n else if ( option==\"data store\"){\n //for ( counter=0; counter2 Bar Magnets, Field Vectors and Field Lines\n

Use this model to compare three linked representations of magnetism: the bar magnets themselves, the magnetic field vectors, and the compass direction at a chosen point.

\n

Suggested Inquiry Sequence

\n
    \n
  1. Start with unlike poles facing. Turn on Field lines and describe how the vectors and streamlines connect the two magnets.
    2. \n
  2. Switch to like poles facing. Look at the crowded region between the magnets. Where do the vectors change direction most quickly?
    3. \n
  3. Use the compass as a probe. Move the compass along one field line and check whether the needle stays tangent to the local field direction.
    4. \n
  4. Hide the field. Use only the compass to infer where the poles must be, then reveal the vectors and field lines to test your prediction.
    5. \n
  5. Rotate one magnet. Explain how the combined field pattern changes when one bar magnet is turned.
    6. \n
\n

Teacher Notes

\n
    \n
  • Vectors show the local magnetic field direction and strength at many points.
    • \n
  • Field lines help students see the overall pattern of attraction, repulsion and curvature.
    • \n
  • The compass offers a third representation: it should align with the tangent direction of the nearby field line.
    • \n
\n\n

Explore More Magnetism Simulations

\n\n" } ] } ] } ], "RootProperties": [] }, "metadata": { "APP": "WebEJS", "CreatedWith": "WebEJS : The web version of Easy JavaScript Simulations", "MoreInfo": "WebEJS 1.1", "version": "https://www.um.es/fem/wikis/webejs/" } }