Closed phet-steele closed 8 years ago
This is definitely a bug. Changing the mass and/or length should not introduce thermal energy. It looks like this issue is present in the Flash version as well.
To elaborate on this issue...
When spinning the pendulums extremely fast and with the minimum length, thermal energy will be spontaneously created and then will vanish.
Since present in the flash version...we will address
Should be no thermal energy now created. Model is accurate to within ~11 digits, AND the thermal energy is not added to at all when friction is off.
On the Energy screen, open the energy graph and set the pendulum swinging. After this, changes in length or mass cause a thermal energy build up even though friction is turned off. It helps to slide these variables back and forth quickly and repeatedly.
Tested on Win 8.1
Troubleshooting information: Name: Pendulum Lab URL: http://www.colorado.edu/physics/phet/dev/html/pendulum-lab/1.0.0-dev.4/pendulum-lab_en.html Version: 1.0.0-dev.4 2015-06-04 17:46:07 UTC Features missing: touch User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101 Firefox/38.0 Language: en-US Window: 1366x633 Pixel Ratio: 1/1 WebGL: WebGL 1.0 GLSL: WebGL GLSL ES 1.0 Vendor: Mozilla (Mozilla) Vertex: attribs: 16 varying: 28 uniform: 1024 Texture: size: 16384 imageUnits: 16 (vertex: 16, combined: 32) Max viewport: 32767x32767 OES_texture_float: true Dependencies JSON: {"comment":"# pendulum-lab 1.0.0-dev.4 Thu Jun 04 2015 11:46:00 GMT-0600 (MDT)","assert":{"sha":"903564a25a0f26acdbd334d3e104039864b405ef","branch":"master"},"axon":{"sha":"7de4a27be4b322b71c5f5046df193a03ccf0f161","branch":"master"},"babel":{"sha":"8725cd18114c1307057c465a0762a3cf8f1cb1b9","branch":"master"},"brand":{"sha":"b3362651f1d7eddb7f8697d02400472f97f9d140","branch":"master"},"chipper":{"sha":"c7d6ea5f9bef6e3882309af56ad409908dd28878","branch":"master"},"dot":{"sha":"a6a50c92c4cda5f8a3371d8c357ea565b7e7bd6c","branch":"master"},"joist":{"sha":"55fd6884039c5ef2f2145093c8530beab5490233","branch":"master"},"kite":{"sha":"b915f3b160744e4833d177dc38e74e4cbc912883","branch":"master"},"pendulum-lab":{"sha":"2b4cf70e4a8a88b37882b1643d44155a806508ab","branch":"master"},"phet-core":{"sha":"23834d107dc1cb368c00901c76927b712b9caa10","branch":"master"},"phetcommon":{"sha":"bb92c52cd90fdaa0c2a746fea82594afd439b4db","branch":"master"},"scenery":{"sha":"f09eddb7393946fcbedb63ebf6b88d1785c91bfc","branch":"master"},"scenery-phet":{"sha":"7ffc5a1a36e0afe36d035d0367078b3558fd157f","branch":"master"},"sherpa":{"sha":"ae2168a85ceb4094c23cd47ba5fe8145375448eb","branch":"master"},"sun":{"sha":"c9087fbb0cdd83f79452330fec3b83f809e2c0d8","branch":"master"}}