# NTNUJAVA Virtual Physics LaboratoryEnjoy the fun of physics with simulations! Backup site http://enjoy.phy.ntnu.edu.tw/ntnujava/

## Easy Java Simulations (2001- ) => Collaborative Community of EJS => Topic started by: lookang on March 15, 2012, 09:34:17 am

 Title: Ejs open source java applet 1D collision force model Post by: lookang on March 15, 2012, 09:34:17 am Ejs open source java applet 1D collision force model by Fu-Kwun Hwanga remix here is by lookangreference:http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=193.0thanks to Fu-Kwun Hwang for this awesome model :) Title: Re: Ejs open source java applet 1D collision force model Post by: lookang on March 15, 2012, 09:37:51 am changes:added m_A and m_B slidersadded Force vs time graphadd flooradd forces vectorsadd force equations which is already provided by F1= getA(x1,x2,m1) and F2 = getA(x2,x1,m2)by Fu Kwun: // awesome codespublic double getA (double xa,double xb,double m) {  if(Math.abs(xa-xb)     if(xa     else return k*(L-(xa-xb))/m;  }  return 0.;} Title: Re: Ejs open source java applet 1D collision force model Post by: babyparty on March 17, 2012, 06:12:20 pm Thanks...for...sharing... Title: Re: Ejs open source java applet 1D collision force model Post by: engrg1 on March 23, 2012, 10:34:47 pm Hi, all.Thanks  to Prof Huang and Loo Kang for the codes.I have edited the codes so that you can show a range of collision type (0: elastic to 1 perfectly inelastic)Have used the equation provided by Ojalvo and Cohen, 1977). You can find the formula @ http://www.brachengineering.com/publications/SAE%202003-01-0491.pdf  (Pg 3)Feel free to give comments. Title: Re: Ejs open source java applet 1D collision force model Post by: engrg1 on March 24, 2012, 09:41:41 am Hi, all.There is some mistake in the formula in the earlier post. I have corrected in this version.It seems that I can't get a perfect value of final velocity based on the coefficient of restitution. I suspect this is due to the modelling equation.Thank to Prof Hwang and Loo Kang again for the codes. Title: Re: Ejs open source java applet 1D collision force model Post by: engrg1 on March 25, 2012, 10:46:30 pm Have modified my previous version with more features (from Loo Kang's initial 1-d collision cart)feel free to give comments!I am still searching for some better equation to model the impact force.Best to run the applet full screen Title: Re: Ejs open source java applet 1D collision force model Post by: engrg1 on March 26, 2012, 08:30:45 am Just realize that this equation is rather correct. The calculation of coefficient of restitution is accurate. I have the wrong idea in the previous post as the e that is displayed is to 1 d.p.  The actual e is very close to the given e.Sorry for the mistake.. Title: Re: Ejs open source java applet 1D collision force model Post by: lookang on March 26, 2012, 09:34:54 am simply awesome remix :)i not sure why it lag Title: Re: Ejs open source java applet 1D collision force model Post by: engrg1 on March 26, 2012, 01:36:57 pm just need to set the frame rate to 100. It should work fine.