Author Topic: Ejs open source java applet 1D collision force model  (Read 9636 times)

lookang

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Ejs open source java applet 1D collision force model
« on: March 15, 2012, 10:34:17 am »
Ejs open source java applet 1D collision force model by Fu-Kwun Hwang
a remix here is by lookang

reference:
http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=193.0
thanks to Fu-Kwun Hwang for this awesome model :)

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lookang

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Re: Ejs open source java applet 1D collision force model
« Reply #1 on: March 15, 2012, 10:37:51 am »
changes:

added m_A and m_B sliders
added Force vs time graph
add floor
add forces vectors
add force equations which is already provided by F1= getA(x1,x2,m1) and F2 = getA(x2,x1,m2)
by Fu Kwun: // awesome codes
public double getA (double xa,double xb,double m) {
  if(Math.abs(xa-xb)  if(xa  else return k*(L-(xa-xb))/m;
  }
  return 0.;
}

babyparty

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Re: Ejs open source java applet 1D collision force model
« Reply #2 on: March 17, 2012, 07:12:20 pm »
Thanks...for...sharing...
« Last Edit: March 17, 2012, 08:35:06 pm by lookang »

engrg1

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Re: Ejs open source java applet 1D collision force model
« Reply #3 on: March 23, 2012, 11:34:47 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.


Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License
  • Please feel free to post your ideas about how to use the simulation for better teaching and learning.
  • Post questions to be asked to help students to think, to explore.
  • Upload worksheets as attached files to share with more users.
Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!

engrg1

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Re: Ejs open source java applet 1D collision force model
« Reply #4 on: March 24, 2012, 10:41:41 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.

Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License
  • Please feel free to post your ideas about how to use the simulation for better teaching and learning.
  • Post questions to be asked to help students to think, to explore.
  • Upload worksheets as attached files to share with more users.
Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!
« Last Edit: March 24, 2012, 12:30:38 pm by engrg1 »

engrg1

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Re: Ejs open source java applet 1D collision force model
« Reply #5 on: March 25, 2012, 11:46:30 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

Full screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License
  • Please feel free to post your ideas about how to use the simulation for better teaching and learning.
  • Post questions to be asked to help students to think, to explore.
  • Upload worksheets as attached files to share with more users.
Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!
« Last Edit: March 25, 2012, 11:52:55 pm by engrg1 »

engrg1

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Re: Ejs open source java applet 1D collision force model
« Reply #6 on: March 26, 2012, 09:30:45 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..

lookang

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Re: Ejs open source java applet 1D collision force model
« Reply #7 on: March 26, 2012, 10:34:54 am »
simply awesome remix :)

i not sure why it lag

engrg1

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Re: Ejs open source java applet 1D collision force model
« Reply #8 on: March 26, 2012, 02:36:57 pm »
just need to set the frame rate to 100. It should work fine.