NTNUJAVA Virtual Physics Laboratory
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Easy Java Simulations (2001- ) => Collaborative Community of EJS => Topic started by: lookang on March 06, 2012, 11:32:00 am



Title: Ejs Open Source Long Magnet Falling Through solenoid Model Java Applet by LTL
Post by: lookang on March 06, 2012, 11:32:00 am
Ejs Open Source Long Magnet Falling Through solenoid Model Java Applet by LTL
derived from http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=2391.0 by lookang
and
original model by http://www.compadre.org/osp/items/detail.cfm?ID=10327 Magnet Falling Through Ring Model
written by Francisco Esquembre.
This simulation was created as part of the MOSEM2 project.
As requested :)
Proper credit made to MOSEM2!!


Made some changes to the applet to make things neat and clear.

    Comparison to motion of a ball is removed. In the worksheet I will ask how the motion of the magnet is compared to a ball and why (Ans: centre of mass motion should be identical. Although emf is induced at the ends of the solenoid, there is no conversion of energy from mechanical to electrical with a open circuit.)
    Remove the simulation in relation to temperature of the coil. Again will ask in the worksheet.
    Modified some of the control elements

I have attached a possible question scenario (will be refined to be a short guided inquiry ~30 mins). Will also produce a short video to demo the feature of the applet.

Question for you:

    how do I embed into your google site for students access?


Title: Re: Ejs Open Source Long Magnet Falling Through solenoid Model Java Applet by LTL
Post by: lookang on March 06, 2012, 11:33:41 am
take the codes from NTNU :)


Title: Re: Ejs Open Source Long Magnet Falling Through solenoid Model Java Applet by LTL
Post by: lookang on March 12, 2012, 12:45:18 pm
added back analysis tool for conducting of investigation that |area| is equal for voltage versus time as the flux change is the same in and out of the solenoid.


Title: Re: Ejs Open Source Long Magnet Falling Through solenoid Model Java Applet by LTL
Post by: lookang on March 27, 2012, 08:04:16 am
fixed bug
ejs_MagnetFallingltlxmlcoil01.jar (1632k) fix bug of NorthSouth pole corrected with correct electron rotation direction  after feedback by RVHS


Title: Re: Ejs Open Source Long Magnet Falling Through solenoid Model Java Applet by LTL
Post by: lookang on September 07, 2012, 08:58:42 am
u can try to reproduce this effect
do you know how?

http://youtu.be/E97CYWlALEs
[youtube=E97CYWlALEs]




increase the B to about 100 T
enjoy!


Title: Re: Ejs Open Source Long Magnet Falling Through solenoid Model Java Applet by LTL
Post by: engrg1 on September 10, 2012, 08:58:04 am
Hi, all.

My attempt to draw the magnetic field.
Please change start_y and start_z to change the initial magnetic field


Title: Re: Ejs Open Source Long Magnet Falling Through solenoid Model Java Applet by LTL
Post by: lookang on October 21, 2012, 06:53:25 pm
This simulation was created as part of the MOSEM2 project.
As requested :)


Title: Re: Ejs Open Source Long Magnet Falling Through solenoid Model Java Applet by LTL
Post by: lookang on December 19, 2012, 04:19:55 pm
more changes
mirror here https://sites.google.com/site/lookang/magnetfallinginsolenoidajc?pli=1


total changes

http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=2391.0
changes made  February 08, 2012, 11:33:47 am » posted from:Rancho Cucamonga,California,United States
lay the magnet correctly now
changes button to face down as in normal convention of the pole going into solenoid
re arrange layout
add check-box electrons
add slider n input fields to all inquiry variables
figure out a way to draw the electrons but the code is not elegant
thanks to paco for his original code
discussion with teacher

I have collated as follows:
1) we need magnet to be of two colors ( red n blue) only. Grey between may give the students the wrong notion that zero emf between the peaks are due to zero magnetic flux.
done!
2) number tagged to every electrons is too near to the rings. Need to space it away from the electrons and ring if possible. So that students can decide the direction of a electron flow and see electron returns when magnet exits.
agree, text = ARIAL BOLD 18
add codes to reposition further

http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=2399.0
changes by tatlee08 March 06, 2012, 12:32:00 pm » posted from:Singapore,,Singapore
Made some changes to the applet to make things neat and clear.
   Comparison to motion of a ball is removed. In the worksheet I will ask how the motion of the magnet is compared to a ball and why (Ans: centre of mass motion should be identical. Although emf is induced at the ends of the solenoid, there is no conversion of energy from mechanical to electrical with a open circuit.)
   Remove the simulation in relation to temperature of the coil. Again will ask in the worksheet.
   Modified some of the control elements

www.phy.ntnu.edu.tw/ntnujava/index.php?topic=2629.0
engrg1 changes September 10, 2012, 09:58:04 am » posted from:SINGAPORE,SINGAPORE,SINGAPORE
Modifications:
(1) Include the Magnetic Field lines (Remix the Magnetic Dipole Field 3D codes by Wolfgang . http://www.opensourcephysics.org/items/detail.cfm?ID=12361]
(2) Magnetic field lines only drawn initially
(3) Link the Strength Magnetic field to magnetic field lines
To change the "shape of the magnetic field", please change the start_y position.

19 December 2012
www.phy.ntnu.edu.tw/ntnujava/index.php?topic=2629.0
added constant velocity capability
but found a bug in the emf induced does not change direction with B = + or B = - values. fixed by added back the negative sign d (rotateElectrons)/dt = -I
added menu to sync with pre-post test questions
added vertical and horizontal view capabilities to sync with pre-post test questions
made the slider values able to dynamically display the instantaneous values for associated learning
added g =0 for constant velocity
added constant velocity and slider with amos input
added induced EMF instead of voltage with amos input
added induced forces with amos input

 



Title: Re: Ejs Open Source Long Magnet Falling Through solenoid Model Java Applet by LTL
Post by: lookang on February 14, 2013, 10:09:19 am
discussion with teacher


In addition, just to clarify some points regarding the applet:
1. When L is increased, we are guessing it is actually the number of turns per unit length which is increased? Why does decreasing L cause the induced V to increase?
2. if that is the case, could you please help us to change parameter 'solenoid length' to 'number of turns per unit length'?
3. Could you also set as default the constant g, vertical case? That will be the bridging point which they are familiar with.

The file can be downloaded from any host of your choice, let you decide.
The file is here
https://dl.dropbox.com/u/44365627/lookangEJSworkspace/export/ejs_FallingMagnet08.jar



my reply
1. Currently, The length is the actual distance occupied by 30 turns
Decreasing L increasing the turns per unit length.

2. Turns per unit length = 30/L, I will change the slider according but I no sure if it is correctly shown, please check.

3. vertical as default with g = 9.81.


Enjoy!

the right panel is modified as per our discussions with another teacher.