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Easy Java Simulations (2001- ) => Collaborative Community of EJS => Topic started by: lookang on December 23, 2008, 02:10:01 pm



Title: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on December 23, 2008, 02:10:01 pm
virtual laboratory simulation for One Dimension collision of two carts allowing inquiry learning for elastic and inelastic studies.
Thanks To Professor Fu-Kwun Hwang for guidance and Professor Francisco Esquembre for EJS and the open source digital library source codes.
Ejs open source, the web applet is from C:\EasyJavaSimulation\EJS_4.1_090609\EJS_4.1\workspace\export\ejs_Collision1Dwee15workingweb.jar
the refined Ejs copy is not deploying correctly in web applet but available as a direct download jar for classroom intervention.
License:
http://creativecommons.org/licenses/by-sa/3.0/sg/

Original code from by Prof. Paco
F:\EasyJavaSimulation\EJS_4.1_081216\EJS_4.1\workspace\source\users\murcia\fem\physics\mechanics\Collision1D.xml

original worksheet by lookang
http://docs.google.com/Doc?id=dff7wgc7_137gthv2kjh&hl=en
Teacher worksheet here on the next page as attachments
http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=831.30
Feedback on Intervention using this worksheets
http://spreadsheets.google.com/ccc?key=pSftDRbvVJyPVPNzwHHHUeA&hl=en


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on December 30, 2008, 09:40:16 pm
Momentum One Dimension Collision Model

The motion of a body of mass m and velocity v is described by a vector quantity known as momentum p where

p = m v

 When objects collide, whether trains, cars, billiard balls, shopping carts, or your foot and the sidewalk, the results can be complicated. Yet even in the most chaotic of collisions, as long as there are no net external forces acting on the colliding objects, one principle always holds and provides an excellent tool for understanding the collision. That principle is called the conservation of linear momentum which states that

 
The total momentum of a system remains constant provided that no external resultant force acts on the system

 
For two bodies colliding linearly, it is written mathematically as a vector equation

 
Total initial momentum = total final momentum

m1.u1 + m2.u2 = m1.v1 + m2.v2


If external forces (such as friction) are ignored, the total momentum of two carts prior to a collision (left side of equation) is the same as the total momentum of the carts after the collision (right side of equation).

Collisions are classified into elastic (or perfectly elastic), inelastic and completely inelastic.

 

There is also a concept of kinetic energy of a moving body is stated mathematically by the following equation:

KE1 = ½ m1.v12



Main Simulation View
The simulation has 2 collision carts on frictionless floor and wheels.
Sliders

Explore the sliders allows varying the variables .

    * mass of cart ONE, mass_1, m1 in kg
    * initial velocity of cart ONE, u1 in m/s
    * mass of cart TWO, mass_2, m2 in kg
    * initial velocity of cart TWO, u2 in m/s

Radio Buttons
Allows for selecting what kind of collision is simulated.

A Perfectly elastic collision is defined as one in which both conservation of momentum and conservation of kinetic energy are observed
A Perfectly Inelastic collision is defined as one in which conservation of momentum is observed but the colliding carts stick together after collision with kinetic energy loss

Checkboxes
show: velocity, for visualizing the velocity vector
plot momentum vs time graph, for different representation of data for momentum of cart 1, 2 and both.
plot kinetic energy vs time graph, for different representation of data for kinetic energy of cart 1, 2 and both.
paused when collide, for visualizing the change in the velocity u1 and u2 to v1 and v2
fast simulation, for cases where the velocity are low and repeat learners can spend time more usefully collecting and analysing data.
hint: COM, for the equation of conservation of momentum
hint: COKE, or the equation of conservation of kinetic energy

Buttons
Play
Step Back
Step Forward
Initialize
Reset
have their usual meaning.
known bug is the Step Back button implementation, please fix it if you can and email me the improved source XML.


Credits:
The Momentum 1D Collision model was created by created by lookang using the Easy Java Simulations (EJS) version 4.2 authoring and modeling tool.  An applet version of this model is available on the NTNU website . Shout our thanks to the Ejs community namely, Francisco Esquembre , Fu-Kwun Hwang and Wolfgang Christian for their professional learning community support. You can examine and modify this compiled EJS model if you run the model (double click on the model's jar file), right-click within a plot, and select "Open EJS Model" from the pop-up menu.  You must, of course, have EJS installed on your computer.  Information about EJS is available at: http://www.um.es/fem/Ejs/ and in the OSP comPADRE collection http://www.compadre.org/OSP/.


Leveraging on Easy Java Simulation tool and Open Source computer simulation library to create interactive d...                                                                                                            
   Publish at Scribd or explore others:            Science              Research                  3rd redesigning peda         
   



Leveraging on Easy Java Simulation tool and open source computer simulation library to create interactive d...                                                                                                            
   Publish at Scribd or explore others:            Science              Research                  integrated elearning              teacher professional         



virtual laboratory simulation for One Dimension collision of two carts allowing inquiry learning for elastic and inelastic studies.
Thanks To Professor Fu-Kwun Hwang for guidance and Professor Francisco Esquembre for EJS and the open source digital library source codes.

My java interactive digital media applet
http://home.phy.ntnu.edu.tw/~lookang/EJS_4.1_081216/Collision1Dwee.html
http://home.phy.ntnu.edu.tw/~lookang/EJS_4.1_090115/Collision1Dwee.html newer
http://home.phy.ntnu.edu.tw/~lookang/EJS_4.1_090208/Collision1Dwee01.html

Good applet model reference:
http://www.walter-fendt.de/ph14e/collision.htm

License:
http://creativecommons.org/licenses/by-sa/3.0/sg/

Original code from by Prof. Paco
F:\EasyJavaSimulation\EJS_4.1_081216\EJS_4.1\workspace\source\users\murcia\fem\physics\mechanics\Collision1D.xml

1 D collision for analysis with Elastic and Inelastic Collision by lookang
Collision 1D
This is a simulation of a one-dimensional collision of two rigid disks.
 
It is a simple example of the event-handling features of the ODE solvers in Easy Java Simulations.
source code
download the *.jar for using the applet on standalone without internet connection.

if you want to recompile without errors with the worksheet graphics, download the 1.4MB jar, expand it, copy the folder Collision1Dwee01 into the source folder location, it should recompile nicely with all graphics available! :)

Modifications done are:
1. rigid rectangles
2. added wheels
3. added floor
4. added panel for inputs
5. added coefficient of restitution e, http://en.wikipedia.org/wiki/Inelastic_collision
6. added plot of KE vs t and Momentum vs t
7. change look for object 1 is RED and object 2 is blue
8. added checkbox for view of plot
9. added buttons of elastic and inelastic selection
10. change buttons to open-source physics.org default ones
11. added deterministic equations C.O.K.E. and C.O.M.
12. added view zoom slider
13. added color change easy
14. added enable buttons only at start of simulation
15. added slider for m1 m2 v1 v2 with closest ticker for inquiry learning
16. added calculation for tcollision and tmaxleft and tmaxright
17. added enable play button only if collision occurs in the view max
18. added stepback() function by using dt = -dt with if else statement
19. added stepforward() function to replace _step() as need a way to remember dt
20. added wheelAngle to rotate the wheel
21. added mass1 and mass2 stored values after reset through a work around after considering initialise method but i decide to do the reset method.
22. added bigger arrows and texts before and after tcollision to alert learners to difference in u1, u2 and v1 ,v2
23. added ??? before hint is shown for t < tcollision
24. added physical detection when press cart1 and cart2, to prevent overlap of carts
25. fix some bugs on enable play button for detecting collision in screen
26. known bug of u1 =0.5 and u2 = 0.5, the play button is still allow........ strange?
27. rearrange the codes for housekeeping less messy
March 11 2009
28. redesign to make look wheel more circle
29. remove hints to suit request to try without from school
30. rearrange bottom panel
31. make graphs to show by default
March 19 2009
32. added graphics of springs and velcro for elastic and inelastic collision
33. added checkbox for values of
m1u1=, m2u2= m1u1+ m2u2=,  
m1v1=, m2v2= m1v1+ m2v2=,  
0.5m1u12= and so on to aid data analysis in worksheet activity, for pattern recognition
March 20 2009
34. added magnets for elastic and velcro for inelastic now with tooltips!
March 21 2009
35. changed to spring for elastic
36. redesign the table for values
January 21 2010
37 fixed a bug of the velcro and springs not draggable and dislocate the carts, now it is activated by on press and on exit, sensitivity at 10 to make it easily to mouse over the velcro TT and spring
January 24 2010 only Available on the standalone jar file http://www.phy.ntnu.edu.tw/ntnujava/index.php?action=dlattach;topic=831.0;attach=1628
38 modify the codes to show partial inelastic collision with an input field of e = 0
39 modify partial to Math.random()
40 remove the number of ticks and closest "false" in order to deploy as a web applet
41 added input field for velocity u1 and u2
42 the appears to be an issue of stability after using Ejs 4.2.7 to compile the source codes, i will investigate and try Ejs 4.2 to test out the codes
March 6 2010
43 made the text for graph click-able as the check-box
44 set x max to tmax as requested by leongster, improving the visual learning of interpretation of the graphs instead of auto-scale immediately
March10 2010
45 added centre of mass as inspired by tatlee08 and http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=5.msg5482;topicseen#msg5482
15 April 2010
46 Fixed an input field of e to be allow to take values from user to allow exploration of e, technique used is assign es to the field
47 made the bottom smaller to fit into the view of width = 750 when web deployed
realized guest accounts canot see attachment which makes my *.jar almost difficult to find by interested learners.
April23 2010
48 increased the sensitivity of cart1 and 2 for ease of drag of carts instead of the exact center
49 added codes to prevent the applet from jamming when the carts are placed at extreme left and right by inserting +0.001 and -0.001 into the x positions of the carts thanks to HY LEE for finding the bug.
50 fixed a calculation of tcollision, remove from evolution page, only in initialization page now because the calculation is deterministic.
18May2010
51 fixed a bug with the time due to the introduction of 49, added -0.001 and +0.001 to the left and right side of the extreme
if (x1>=(max-radius1-0.001) || x1<=(-max+radius1+0.001) || x2>=(max-radius2-0.001)|| x2<=(-max+radius1+0.001))
{
_pause();
}
52 added the worksheets and suggested answer key into the jar file for ease of scaling to other classrooms in the world
53 added portuguese language translated by ahmedelshfie, thanks!
26May2010
54 added game like assessment of learning input fields for students to check for understanding thanks to student feedback from rvhs http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=831.msg6291#msg6291
55 made color background of last column uniform
29May2010
56 finer customization of assessment for learning game feedback now recognize elastic and inelastic and partial
57 added sound effect for collision for partial and inelastic, elastic has no sound because real life use like poles of a magnet to repel simulate collision refer to http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=824.0 for sound adding
58 added data analysis tool for graphs data like tracker
59 worksheets and suggested answer all packed inside the jar, 1.6 mb file now.
15 June 2010
60 remove the "pause when collide" checkbox since it seems to not work anymore
61 width = 600 resized
31 March 2011
made all the vectors point to the right by adding Math.abs() for consistent pen paper discussion
made the table editable for clearer values though it cannot be edited, for journal paper graphics


i started doing html again in EJS4.1 16 dec 2008 version

this is another world class applet in my view, built on the strengths of open source, and contribution by great man like prof paco and prof hwang.

addition improved in next version:
a prediction  of collision before showing the 2 equations of MOM and COKE  ::) because it did not collide and the equations shown are for assumed the is a collision.

any help is appreciated


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: Fu-Kwun Hwang on December 31, 2008, 09:58:28 am
I just modified the code. Guest can view attachment file now.

You can add another variable show_equation (initial value: false) and set it's value to true when detect collision. :-)


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on December 31, 2008, 10:35:19 pm
I just modified the code. Guest can view attachment file now.
Thanks!

You can add another variable show_equation (initial value: false) and set it's value to true when detect collision. :-)

I have a boolean variable for collision

now i fixing another issue with the display of u1, u2, v1, v2. still improving it with deterministic time to reach the edge of max view.
will post automatically when ready!


Made a Youtube



YouTube. Was stuck at Portland airport from 11pm to 4am, decided to use the time to make some promotional video on the applets shared during 2010 AAPT Summer Meeting in Portland, Oregon


Some demonstrations of various types of collsions along a low friction track.  


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on January 03, 2009, 10:53:58 am
i can't make the wheels rotate by using the rotate function as in the EJS 4.1. the object does not have a rotate option but a transform option that seems to only take constant value like

ro:45d

but not ro:wheelAngle


where wheelAngle is = x1/radius1 ; // formula for s = r*teta


after compiling, it does not seems to take the value of wheelAngle as x1 changes.

i suspect it could be a bug or area of improvement for future EJS version?

thanks for looking into this matter.


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: Fu-Kwun Hwang on January 03, 2009, 04:30:15 pm
I just tried it. It seems to work fine.
Set the Transform property to wheelAngle should be fine.


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on January 03, 2009, 09:35:59 pm
can look at my xml, wheel01 and wheel02 have transformation but they do not rotate.

it is puzzling me ???


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: Fu-Kwun Hwang on January 03, 2009, 11:15:40 pm
You did not change the transformation as I indicated above.
You set it to
ro:wheelAngled
However: no variable defined as wheelAngled available.
Change the above to
wheelAngle
(Yes. Without ro:)
And it should work (for wheel01 and wheel012).


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on January 04, 2009, 08:27:42 pm
(Yes. Without ro:)
And it should work (for wheel01 and wheel012).

Yes! thanks ! without any ro:

just wheelAngle in the transformation. got it to work now! cool


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on January 19, 2009, 04:35:31 pm
Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on February 10, 2009, 01:09:21 pm
I am starting a small study on using this EJS made virtual lab.

Outcome to aid learning:
Inquiry Learning Worksheet to complement this virtual lab.



i found a couple of interesting worksheets .
http://users.salineschools.com/~frederth/Physics/Unit9/LabConsMomentum.pdf
http://physicslabs.cwru.edu/MECH/Manual/Worksheets/COL.pdf
http://www.pasco.com/resources/labdownloads/word/glx/physics/14%20Momentum%20SV.doc



Do you have one that i can adapt to this virtual lab on elastic and inelastic collision momentum and kinetic energy?


trying to improve the usability of applet virtual lab


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on February 17, 2009, 04:02:37 pm
first draft of the worksheet to complement the virtual lab.

hope to capture:

1. inquiry learning
2. allows self directed learning
3. has collaborative social group work learning
4. promote critical thinking.



changed to tatlee08@gmail.com , weelookang@gmail.com  for feedback


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: LeeTl on February 19, 2009, 04:08:27 am
Look thru your work sheet. It would be interesting if the students also have a hands-on to compare theory and practice. Can we:
1) Split class in half - one use the applet another using the collision carts but with similar worksheet. Then get them together to compare their solution.
2) Do the same task using applet and collision carts. However this will not generate much discussion


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on February 19, 2009, 07:55:05 am
Look thru your work sheet. It would be interesting if the students also have a hands-on to compare theory and practice. Can we:
1) Split class in half - one use the applet another using the collision carts but with similar worksheet. Then get them together to compare their solution.
.


My thoughts:
Actually my previous school did the real lab in 2007, it is very difficult to setup with data loggers and can't vary mass easily, the range of space for collision also need about >0.5m for data logger to read distance of the carts. But if you sure you want a side by side intervention, just be ready for chaos in the real lab and lots of time for trouble shooting.

My position:
I am okay with both as long as you are :)
Let's discuss more  what is our research question.

My take on EJS vs Real Data logger lab
My experience tells me both (real and virtual) will have advantages and disadvantages over the other method.

A great teacher (CHEE YS) once enlightened us:
It is not about which is better, black vs white paradigm, it is about bringing the best of both the virtual world and real world to achieve meaningful learning for students, the degree of both as to speak "blended learning"?

My original idea:
Let me go find the research that just record their journey, I hope it is more impactful & meaningful.
research less, students learn more & teach less, learn more.



2) Do the same task using applet and collision carts. However this will not generate much discussion

My thoughts:
I have my doubts about that being a fair comparison.
I doubt real lab allows the degree of self directed learning, provide by EJS virtual lab.
Virtual Lab are

1. safe inquiry
2. easy setup
3. 1 to 1 exploration of science
4. time
5. any time, any place



Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on February 20, 2009, 01:05:48 pm
found this cool flash of similar design and intent.

http://www.physics-lab.net/applets/one-dimensional-collisions
http://www.physics-lab.net/appletsold/1dcollisions/1dcollisions.swf

i didn't flash it here using flash codes for copyright
says gavin lobo



good flash there,

i got an improvement idea .
1. to show the equations of COM and COKE only after there is collision t > t collision
else show left side of the equation only with the usual ????

found some good applet on collision

http://www.walter-fendt.de/ph14e/collision.htm (http://www.phy.ntnu.edu.tw/ntnujava/index.php?action=dlattach;topic=831.0;attach=2663;image)

https://www.msu.edu/~brechtjo/physics/airTrack/airTrack.html (http://www.phy.ntnu.edu.tw/ntnujava/index.php?action=dlattach;topic=831.0;attach=2665;image)

http://dept.physics.upenn.edu/courses/gladney/phys1/lectures/lecture7/momentum_conservation.html(http://www.phy.ntnu.edu.tw/ntnujava/index.php?action=dlattach;topic=831.0;attach=2667;image)

http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=5 (http://www.phy.ntnu.edu.tw/ntnujava/index.php?action=dlattach;topic=831.0;attach=2669;image)

http://66.7.205.91/~lookangc/index.php?topic=1009.0(http://www.phy.ntnu.edu.tw/ntnujava/index.php?action=dlattach;topic=831.0;attach=2671;image)

http://webphysics.davidson.edu/physlet_resources/bu_semester1/c13_elasticity.html  (http://www.phy.ntnu.edu.tw/ntnujava/index.php?action=dlattach;topic=831.0;attach=3443;image)


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: Fu-Kwun Hwang on February 20, 2009, 02:12:29 pm
The center of mass is not at the same position before/after the collision.
It is fine, if you change the velocity to 2.6 and -2.6
But you will not be able to set velocity to 2.5 or -2.5 again if you have dragged the slider.
It is a minus bug in the code.
You can ask students: what is wrong in the simulation!
May be they can find out more. This is another way of learning. (Could be fun,too!).

You are welcomed to find out if there is anything wrong in my simulations,too!
We all make mistakes! At least, I do!  :D


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on February 20, 2009, 02:27:52 pm
The center of mass is not at the same position before/after the collision.
It is a minor bug in the code.It is fine, if you change the velocity to 2.6 and -2.6
agreed, i notice the flash did make that calculation error.


I just like to add that EJS open source codes approach path the way forward for human knowledge creation, the simulation takes on a life of it own and lives on.   ;D

I love open source


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on March 03, 2009, 09:27:59 am
i am trying to make the 2 carts not overlap each other.

i inserted this custom function:

"drag ();" inside the graphics of the body1 under the on drag field.


the codes are:

public void drag () {
//double aaa =Math.abs(x1-x2);
/ x1 is position centre of cart1
//x2 is position of cart2
//radius1 is length centre to edge of cart1
//radius1 is length centre to edge of cart2


if ( Math.abs(x1-x2)<(radius2+radius1) )  /
{
  x2 = x1+(radius2+radius1);
// i used the idea of function to make cart1 on drag to make x2 some equal distance from x1 to give the appearance of push together due to physical constraint touching together if  Math.abs(x1-x2)<(radius2+radius1)but it cannot work??

}//  x1 = -2*radius1+x2+2*radius1;
// x2 = x1+2*radius1-2*radius1;
 
}
could it be the i have codes is causing the codes not to work?
it look correct but don't know why nothing happens like i intended with the codes.


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: Fu-Kwun Hwang on March 03, 2009, 10:08:22 am
1. You can write code directly inside the action property field.
I define custom function when it is used more than one places.
2. What you did seem to be correct. May be there are something wrong at other places.
 Please upload your xml file so that I can check it.


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on March 03, 2009, 10:58:33 am
i also thought i did it correctly.

sorry i got a lot of tabs in the xml, short codes so that i can follow myself, and do simple copy and paste if i need to remixed into other xml, it looks messy but i prefer this to a one tab with many sections of codes.

thanks!


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: Fu-Kwun Hwang on March 03, 2009, 12:38:36 pm
It works when I add the following code to the end of "Fixed relation" page.
Code:
if ( Math.abs(x1-x2)<(radius2+radius1) )
{
  x2 = x1+(radius2+radius1);
}

It means you have a command set x2=0.0 in one of your tabbed pages
(either _initialize pages or Fixed relation pages) or
You have so many pages, I can not find it. (I would suggest you find a better way to organize your pages!

Check out the attached xml



Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on March 03, 2009, 10:52:30 pm
thanks! will do some housekeeping.



Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on March 18, 2009, 11:08:44 pm
will do some real student learning on 23 25 26 / march 2009. thanks to LeeTl

it will be based on virtual laboratory type of worksheet.


i doubt the school education system encourage student construct and modify EJS codes constructionism type of learning.
Maybe i can explore more along this direction when i go back to teach in class in 2010 July. :D


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: Fu-Kwun Hwang on March 19, 2009, 06:54:09 am
Great! I hope students can enjoy the fun of physics playing the inquiry activity!


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on March 21, 2009, 04:30:19 pm
it is true that after a XML file reach a certain file size say 250 KB, the EJS seems to be a bit laggy during the open file process?



mine like stuck a long time, hope the  file is not corrupted or something.

If you got time, can try to open this file attached ?

thanks!


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: Fu-Kwun Hwang on March 21, 2009, 04:45:12 pm
There are a lot of image files in your xml source.
It will take time to read all the images into EJS  and eat up memory quickly.
If the image files are only needed in the intorduction page. You can write those information into a html file and include html into EJS. This might help (However, I have never tried it before. So I really do not know.).


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on March 22, 2009, 06:24:27 pm
i seem to be unable to load the applet here.
i can load the others on other pages with no problem.

can anyone verify "unable to load the applet here"?

i suspect the "Modify EJS Simulation" function checkbox maybe does not allow too many uploads? or some how i uploaded jar files that mess up the "Modify EJS Simulation" function ?

Thanks!


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: Fu-Kwun Hwang on March 22, 2009, 06:59:38 pm
Downloaded jar file work fine.
The problem is: this page was not able to show the applet properly.


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on March 22, 2009, 09:49:08 pm
i found the cause of the problem to load in the web deployment.

immediately after i delete the group 2d in the view, which i used to create the graphics of magnets,
the applet loads again on the web here.

for those who are interested file Collision1Dwee07.xml has the group2D graphics which will cause a failed web applet though the jar works independently if launched as a jar standalone app.

Collision1Dwee08.xml has the has the group2D graphics deleted and all is wonderful again.
web deployment works again!!!

thanks for testing on your end prof !

i will delete the test posts now!


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on March 23, 2009, 08:59:25 pm
i don't understand why it fail to load the web applet. now again. strange


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on March 25, 2009, 06:13:25 pm
on 23march 2009 in a class of 24 in a typical pre u one setting of a physics lab session 1 hr 40 mins

the data collected are as follow
http://spreadsheets.google.com/ccc?key=pSftDRbvVJyO-7VdOdF9BHQ&hl=en
How much do you know about the physics of collisions between two bodies before this lesson?   
A great deal   1   2   3   4   5   Very little      3.29
How much do you know about the physics of collisions between two bodies after this lesson?   
A great deal   1   2   3   4   5   Very little      1.92
How much do you feel you have learnt or accomplished in this laboratory lesson?   
A great deal   1   2   3   4   5   Very little      2.29
If the concept of collisions is introduced through lectures with examples, would it generate the same amount of interest?    
Yes, a great deal   1   2   3   4   5   No, very little   3.21
Do you learn better from a hands-on activity than a lecture?   
Yes, a great deal   1   2   3   4   5   No, there isn't any difference      2.38
I enjoyed learning about the learning about the physics of collisions through this laboratory …   
Very much   1   2   3   4   5   Not at all      2.50
How interesting and stimulating were the activities?   
Very interesting   1   2   3   4   5   Very boring      2.38
How much did this lesson challenge you to think?   
A great deal   1   2   3   4   5   Very little      2.71
Rate the lesson as a learning experience.   V
ery valuable   1   2   3   4   5   Worthless      1.92
Would you want to attempt similar lessons for other topics in the future?      
Yes   No               20 Y 4 N   83% Y
Were you given adequate instructions for proceeding with the lab work?   
Yes, a great deal   1   2   3   4   5   None was given      1.79
Were you given adequate assistance during the lab work?   
Yes, a great deal   1   2   3   4   5   None was given      1.63
Did you have adequate time to complete the lab work?      
Yes   No               17 Y 7 N   71% Y
How much effort did you put into this lesson?   
A great deal   1   2   3   4   5   Very little      2.13

10   Elaborate whether you want to attempt similar lessons
   (Comments by students)
Yes   Hands-on learner
Yes   Autonomy to try out different situations
Yes   Learn better and clearer this way
Yes   Instill concepts and understanding through a clear learning process
Yes   See physics theory comes to life, make it easier to understand
Yes   Expt is interesting
Yes   Hands-on is interesting
Yes   Good alternative to usual lab
Yes   Fun and engaging
Yes   More hands-on, better than lecture
Yes   Interactivity keeps me awake
No   Not interesting
No   Too theoretical and troublesome
No   Prefer lecture for theoretical study

15   Is there any thing that you feel should be done to enhance the effectiveness of this lesson?
   (Comments by students)
   Air-con room keeps us awake and absorb better
   More this kind of lesson
   More fun activities
   It's flawless
   More engaging activitiy (No to Q10)
   Lesson is effective enough
   A little more challenge
   Have better graphics
   Applet could be more vivid
   Lesson is well-planned and effective
   Lesson was very concise and effective as it is
   Less amount of trials should be conducted
   Quite effective

16   Other comments
   (Comments by students)
   Air-con room
   Thanks for the effort
   Lesson lasts too long
   Easy to comprehend
   Applet keeps hanging

attached are the worksheets feedback from LeeTI


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on March 25, 2009, 06:19:33 pm
on 25march 2009 in a class of 14 in a typical pre u one setting of a physics lab session 1 hr 40 mins


   Questions   Likert scale                     Total   Average
1   How much do you know about the physics of collisions between two bodies before this lesson?   
A great deal   1   2   3   4   5   Very little      3.50
2   How much do you know about the physics of collisions between two bodies after this lesson?   
A great deal   1   2   3   4   5   Very little      1.79
3   How much do you feel you have learnt or accomplished in this laboratory lesson?   
A great deal   1   2   3   4   5   Very little      2.21
4   If the concept of collisions is introduced through lectures with examples, would it generate the same amount of interest?    
Yes, a great deal   1   2   3   4   5   No, very little      3.64
5   Do you learn better from a hands-on activity than a lecture?   
Yes, a great deal   1   2   3   4   5   No, there isn't any difference      1.86
6   I enjoyed learning about the learning about the physics of collisions through this laboratory …   
Very much   1   2   3   4   5   Not at all      2.07
7   How interesting and stimulating were the activities?   
Very interesting   1   2   3   4   5   Very boring      2.14
8   How much did this lesson challenge you to think?   
A great deal   1   2   3   4   5   Very little      3.00
9   Rate the lesson as a learning experience.   
Very valuable   1   2   3   4   5   Worthless      1.93
10   Would you want to attempt similar lessons for other topics in the future?      
Yes   No               14 Y 0 N   100% Y
12   Were you given adequate instructions for proceeding with the lab work?   
Yes, a great deal   1   2   3   4   5   None was given      1.71
13   Were you given adequate assistance during the lab work?   
Yes, a great deal   1   2   3   4   5   None was given      1.57
14   Did you have adequate time to complete the lab work?      
Yes   No               14 Y 0 N   100% Y
17   How much effort did you put into this lesson?   
A great deal   1   2   3   4   5   Very little      2.57


10   Elaborate whether you want to attempt similar lessons
   (Comments by students)
Yes   working independently on a computer is more fun as compared to listening to a lecturer talk about examples
Yes   much easier than normal practical sessions
Yes   it is more interesting compared to normal lessons and lecture and allow to understand easier than lecture through hands on
Yes   we get to experience the real life application of physics and this hand on task motivates us to think more in depth
Yes   it is not as mundane as just attending lectures because being able to conduct our experiments through means like simulation will allow us to find out results and understand better
Yes   it is more interesting than in lecture style
Yes   it is very fruitful it is a break from all the other normal lessons
Yes   good link to the topic act as application example emphasize on the key points of the topic
Yes   it is very interesting and practical therefore it is easier to remember and understand
Yes   it is more effective to convey knowledge using a practical way
Yes   hand on activity is more interesting and is easier to learn from than lectures
Yes   it is fun and interesting
Yes   interesting
Yes   it is ore interesting and i will be less likely to fall asleep
15   Is there any thing that you feel should be done to enhance the effectiveness of this lesson?
   (Comments by students)
   add stuff to do
   nicer application more hands on rather than using the computer
   be more strict with the time limit
   there can be more tasks to complete
   make applet more beautiful and colorful it will be more exciting
   application should be more colorful and fun there should be more animation in the application
   
   
   
   
   
   
   
16   Other comments
   (Comments by students)
   cars can be used instead of boxes for objects of collision
   the session is too long


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on March 27, 2009, 05:21:28 pm
From my EJS console:
Basic options:
Your Java VM is: C:\Program Files\Java\jre6
Advanced options:
Use Java VM: C:/Program Files/Java/jre6/
Virtual Machine parameters: -Xmx256m
setting Advanced options: Use Java VM: C:/Program Files/Java/jre6/ seems to be the magic i needed to make my applet work on the web display!

i will try again.

thanks!


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on March 29, 2009, 02:58:25 pm
i don't know why but it doesn't work for me.

since it is taking me forever to figure out the problem with web applet, ejs applet standalone works well.

can you help me reloaded in the first post of this topic, just download the XML, recompile on your pc, modify in first post of the topic, so that everyone else can see the applet in web .

Thanks!

and thanks for deleting the test topics too :D


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: Fu-Kwun Hwang on March 29, 2009, 03:01:17 pm
I can not find any xml file from the first posted message?


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on March 29, 2009, 03:05:08 pm
thanks!


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: Fu-Kwun Hwang on March 29, 2009, 03:46:46 pm
It is working when I upload it to here! (it is not working when I upload to the first message -- may be due to browser cache issue?)


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on March 29, 2009, 10:23:32 pm
checked out the first post! ;D

it finally worked but not the best version that remembers v_temp1 and v_temp2.

currently to solve the web deployment problem, i need to assign

v_temp1=-1.2000000000034206E-4
v_temp2 = -1.2000000000034206E-4

is it some double values that after playing with the applet, the XML automatically generated this values that i initially i left them as "BLANK".

so i copied -1.2000000000034206E-4 into the variables and it works now.

the bug could be this XML as i could easily upload and web deploy any other XML.

nevermind, it is a good applet still though the applet reset u1 and u2 to zero.


by the way
did you read the comments from the 78 students feedback?
http://spreadsheets.google.com/ccc?key=pSftDRbvVJyPVPNzwHHHUeA&hl=en

it is encouraging data, shows students generally want to learn from doing/inquiry rather than show and tell lectures system in most educational setting.

I knew Ejs is a great tool for many reasons, thus i am learning to make applets for many virtual labs than supports/complements learning.

me and my frd LeeTI intend to do another virtual lab on SHM which i have already made.

thanks for all your help and support prof hwang!


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: Fu-Kwun Hwang on March 29, 2009, 11:48:11 pm
You should give all the variables defined in the model an initial value.
Computer can not and should not determined it for you.

EJS will generate for you if you drag slider/ or if do some action on the editor view window (the window for you to create the view).
I do not know what those two variable v_temp1 and v_temp2 are defined for. So I do not know how to help.


A new change in EJS 4:
The property for the number of element shown can not be 0 when you use particleset/elementset...  etc.

I used to set the number of elemet to a variable, and none of the elements will be shown when the variable is zero in EJS 3.4.   However, it will not wok any more since EJS4.

If the same elements needed in the simulation are nore than two, I will use element sets instead.
But you create all the elements one by one.  So it is not a problem for you!


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: Fu-Kwun Hwang on March 29, 2009, 11:50:52 pm
It is working fine with my browser! (I can view applet at the first message now)

Is it possible that the error was due to some image files was not available for web page?
You need to tell ejs to include all the images/resources files used in the ejs, so that EJS can include those file in the generated jar file. Please check out the attached image for EJS interface to include resource files.


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on April 26, 2009, 10:12:01 pm
some pictures to go with the experiment.

creative commons attribute license


Title: Re: 1 D collision for analysis with Elastic and Inelastic Collision by lookang
Post by: lookang on May 27, 2009, 12:33:13 pm
when time permits will add function to address

Dynamics
Linear momentum and its conservation

(g) state the principle of conservation of momentum.
(h) apply the principle of conservation of momentum to solve simple problems including elastic
and inelastic interactions between two bodies in one dimension. (Knowledge of the concept
of coefficient of restitution is not required.)
(i) recognise that, for a perfectly elastic collision between two bodies, the relative speed of
approach is equal to the relative speed of separation.
(j) show an understanding that, whilst the momentum of a system is always conserved in
interactions between bodies, some change in kinetic energy usually takes place.
http://www.seab.gov.sg/SEAB/aLevel/syllabus/2010_GCE_A_Level_Syllabuses/9646_2010.pdf


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on August 03, 2009, 12:06:58 pm
pdf versions for iphone users

Paper in pdf


Powerpoint in pdf

01 Feb 2010
removed due to lost of attachment


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on November 07, 2009, 11:37:14 am
found another Ejs java applet by duffy@buphy.bu.edu Andrew Duffy  http://www.compadre.org/portal/items/detail.cfm?ID=9426

http://physics.bu.edu/~duffy/Ejs/EP_chapter07/Collisions1D_v1.html for learning the same concept about 1D collision!
*like
the check answer feature seems cool to allow learners to test themselves like a game.
when time permits will add a pop up game like interface for keying in!

some other cool applets on collision
Virtual Air Track http://www.lon-capa.org/~mmp/kap6/cd157a.htm
Conservation of Momentum - 2 Mass Elastic Collision http://qbx6.ltu.edu/s_schneider/physlets/main/momenta3.shtml
Elastic and Inelastic Collision by Walter Fendt http://www.walter-fendt.de/ph14e/collision.htm


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on January 08, 2010, 06:24:31 pm
My teacher friend is going to scale and translate this applet for his school by the whole level.
A team of physics teachers will be using this applet like a virtual practical lesson!!
Cool right?
will post more development as we journey on using ICT for meaning learning.

All these is possible because of Ejs and people like U, Prof Hwang!
Thanks!


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: Fu-Kwun Hwang on January 08, 2010, 08:50:23 pm
It is great to hear the good news. I hope those students can enjoy the fun of physics as I do!  :)


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on February 01, 2010, 03:50:43 pm
I managed to fixed some bugs and improve usability as suggested from (01 Feb 2010) today's session.

Bug:
Occasionally the virtual lab java applet hangs due to runtime error
Solution:
I removed codes that causes runtime error
I recompiled using an Ejs 4.2 (older version) and it seems to working better now :)
Else if that didnt work, the lab computers may benefit from java runtime update (latest) version 18, they all still on update version 5.


Usability:
Students/ teachers feed back the slider for velocity need to snap to closest
I reworked it, it should work snap to integer values now.

My Observation/Reflection:
students seems to be able to complete the activity assigned on the table in 10-15 minutes, they then go around and copy the inquiry data from the other teams, which I noticed students seem to be copying very quickly, probably with little thought about the patterns of the physics ideas.
Suggestion:
May I suggest  to allow each pair of students to investigate all the 32 sets of data, based on the suggested inquiry category (head-on, tail collision, stationary etc that was provided as scaffolds). The collaborative aspect could be more on proposing and sharing of hypothesis of the physics ideas, less on the raw data exchange part. What do you think?

My Reflection:
Students were not concluding the patterns of the collected data, until I went round to help them draw logical conclusions.
Suggestion:
Teacher has to go around and facilitate more, to prompt and ask questions about the patterns of the physics ideas simulated by the virtual lab supported by the filling in the activity worksheets.

The latest applet is at the first page of the post.
I had to removed the velocity slider snap to closest as it is causing the web applet to fail to load.


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on February 13, 2010, 04:05:29 pm
the video to share the message of using virtual lab to learn by doing.


this video was made to share some implementation tips and best practices and of course students feedback that affirms the learning strategy through virtual lab pedagogy.
enjoy!


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on February 19, 2010, 02:19:51 pm
Attached are it the zip file for the
Feedback Form and Teacher's Notes
Suggested answer for Collisions between two bodies – Virtual Laboratory Combined elastic & inelastic Inquiry learning application tasks
Collisions between two bodies – Virtual Laboratory Combined elastic & inelastic Inquiry learning
Collisions between two bodies – Virtual Laboratory Combined elastic & inelastic Inquiry learning application tasks
Suggested answer for Collisions between two bodies – Virtual Laboratory Combined elastic & inelastic Inquiry learning

Write up

Lesson Idea Synopsis
A co-created virtual lab learning environment was designed with guided discovery worksheets to support the process of sense making of the physics of collisions. Students investigated into the relationship between the variables collaboratively in groups of 2 to 3, and also shared their analysis through short presentations, for other students to critique.
Actual lesson learning environment (java applet) can be downloaded here
http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=831.0

Instructional Objectives
Candidates should be able to:
1. apply the principle of conservation of momentum to solve simple problems including elastic
and inelastic interactions between two bodies in one dimension.
2. show an understanding that, whilst the momentum of a system is always conserved in
interactions between bodies, some change in kinetic energy usually takes place.

 How was the lesson carried out? (Please include level, ICT equipment & resources needed, pedagogy or strategies used, thinking skills taught, if any, duration of lesson, etc)
Self-directed learning (SDL)
Ownership of Learning, students set and identify variables to inquiry on, for example, mass (m1 and m2), initial velocity (u1 and u2), type of collisions (perfectly elastic, partially elastic and perfectly inelastic). Learners have to decide type of variables to inquiry, for example, momentum, kinetic energy, relative speed of approach and separation etc.
Management and Monitoring of own Learning, students explore experimental data and make logical arguments and findings.
students formulate questions and generate own inquiries when conducting the virtual experiment guided by the worksheets.
Students use the feedback form to improve their experience in using the virtual lab.
Extension of Own Learning
Apply learning in new contexts is supported by the application worksheet where they conduct a problem based learning scenario of a crash site between a lorry and a car by examining the evidences of skid marks on the road etc.
Learn beyond the curriculum, students are expose to the concept of coefficient of restitution, e and getting a larger schema of the equations of collision taught in university courses.

Collaborative Learning (CoL)
Effective Group Processes, in pairs the students need to negotiate and set common goals to explore in the lab
Individual and Group Accountability of Learning, students learn in pairs, share their findings in short oral presentations, supported by peers evaluation.

The lesson was carried out with year 5 (JC1),
ICT equipments used included Computers, with Java Runtime installed, Ejs open source java applet 1D collision carts Elastic and Inelastic Collision 1mb file copied into the desktop.
Pedagogy is Learner centred learning with technology.
Strategies Teacher as technology, content, pedagogy and knowledge expert (TPCK), facilitating the inquiry learning process, with teacher to facilitate at suitable times.
Thinking skills, Self directed planning of inquiry approach is required for students to collect data, Science Practical Assessment Skill A. Analysis of data skill is also practiced. Evaluation of data and finally Synthesis skill during the proposing and verifying of their hypothesis of the physics principle .
Lesson is 1 hour 40 mins
 

How did ICT value-add to the learning process? How did the use of ICT change the learning and teaching process?
ICT added value because
1. safe inquiry, lesser chance of injury during physics practical as there is no physical objects moving or falling off apparatus etc.
2. easy setup with virtual labs, real life setup is difficult to calibrate the motion sensors, lack of sufficient number of practical sets
3. 1 to 1 exploration of science principle
4. time spent on learning increased, less time spent on debugging the real life data logger setup with connecting wires, faulty sensors, inaccurate data collected, less variables can be varied reliably.
5. support any time ( no restricted to that practical lesson ), any place ( home based lessons is possible)
 

What were the outcomes? (Benefits to pupils or teachers, re-designing of pedagogy, development of staff, etc)
Benefits to students as collected in the feedback forms are
Yes Hands-on learner
Yes Autonomy to try out different situations
Yes Learn better and clearer this way
Yes Instill concepts and understanding through a clear learning process
Yes See physics theory comes to life, make it easier to understand
Yes Expt is interesting
Yes Hands-on is interesting
Yes Good alternative to usual lab
Yes Fun and engaging
Yes More hands-on, better than lecture
Yes Interactivity keeps me awake
Teacher benefit is he is more convinced that he is doing something meaningful to engage his students.

Re-designing of pedagogy is still teach less, learn more (TLLM), make the learners the centre of learning activities.

Development of staff is teachers learn to design learning environments (java applets), design worksheets to implement meaningful ICT lessons.
 

How did you assess student's learning using ICT? (Examples of work produced, etc)
Students work were captured in the worksheet.
Students interviews indicate the ICT lesson enables them to learn on their own, more engaging than exisitng lecture style of information delivery system.
Students feedback affirmed the physics teachers professional learning community (PLC) effort.

Do you consider the ICT lesson a success? What went well? What would you do differently next time?
some selected comments from students:
"More this kind of lesson
More fun activities
It's flawless
Lesson is effective enough
Lesson is well-planned and effective
Lesson was very concise and effective as it is
Less amount of trials should be conducted
Quite effective"
Differently, Students suggested that
"Air-con room keeps us awake and absorb better
A little more challenge worksheet, maybe engage them in the modeling aspects of the physics or improving the worksheet.
Have better graphics
Applet could be more vivid".

What went well?
Teachers going around to help the groups of students make sense of their own inquiry on variables like real scientists.

What would you do differently?
the teachers role is critical to promote the learning and sense making process, the teacher has to go around the groups to facilitate and ask the groups to make their own logical conclusion and hypothesis.
 

Will you be conducting this lesson again? If so, when will it be? (E.g., Term 3 in 2010; on-going, etc)
Yes, It will be conducted yearly, usually term 1 JC1.
There is a level wide scaling and translation to all JC1 physics classes from 2010.
With this lesson example, it is hoped that all interested will use this virtual lab to impact their schools physics curriculum through technology.
Please feel free to use it for your classroom.


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on March 10, 2010, 09:43:38 pm
the applet is on the first post.

March10 2010
45 added centre of mass as inspired by tatlee08 during his classroom interaction with his students and http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=5.msg5482;topicseen#msg5482

added centre of mass to illustrate the concept of COM, u will notice by playing and selecting the centre of mass checkbox that the velocity of CM is constant throughout the motion, therefore (m1+m2)(vcm) is also true.
enjoy!


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on April 15, 2010, 03:41:56 pm
testing D:\EasyJavaSimulation\EJS_4.2.7_100314\EJS_4.2.7 whether the export is working for web deployment.

15 April 2010
46 Fixed an input field of e to be allow to take values from user to allow exploration of e, technique used is assign es to the field


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collisi
Post by: lookang on May 17, 2010, 10:08:12 am
added directly using the *.jar file the translation for portuguese pt. thanks to ahmed's original translation to brazilian portuguese brpt.
This is my first translated applet by ahmed which i helped to re-key in. It is ready for more translation to more languages, please help by downloading *.jar and key in and re attached as attachment, i will attribute the translators!

Thanks ahmed for translation to portuguese !! ;D ;D

it is on the first post now.
only available after u download the *jar file, not yet possible on the web deployed applets.


Oh, Prof Hwang, i didn't continue to use the web based translator because the  brazilian portuguese characters i keyed in were cut off.
for your info.

for example,
View.drawingFrame.title    = Colis = Colisão elastica e inelática

by the way, does anyone know where the files for the translation are kept in Ejs? i thought i saw before but i could not find it after unzip the folder of the *jar file.


Oh, Ahmed i also translated to english your copy of the applet. attached! enjoy! :D


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: Fu-Kwun Hwang on May 17, 2010, 01:44:22 pm
A new subdirectory xxx_pkg will be created when translation was done, where xxx is the same name ejs xml source.
And there is a file xxx_zh.properties will be generated in the sub-directory if it is for traditional Chinese characters.

Quote
Oh, Prof Hwang, i didn't continue to use the web based translator because the  brazilian portuguese characters i keyed in were cut off.
for your info.

The web based translator find the user's language code for utf-8 transfer.
You will have problem if you try to translate portuguese characters.
It should be fine if it was done by ahmed.


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on May 17, 2010, 04:21:17 pm
A new subdirectory xxx_pkg will be created when translation was done, where xxx is the same name ejs xml source.
And there is a file xxx_zh.properties will be generated in the sub-directory if it is for traditional Chinese characters.

I re-expanded the jar which had the 2 languages english and portuguese.
D:\EJS_4.2.7_100314\EJS_4.2.7\workspace\export\ejs_Momentum1D2010web01\users\sgeducation\lookang\Momentum1D2010web01_pkg
but there is no

Momentum1D2010web01_pt.properties
Momentum1D2010web01_en.properties

only this (http://www.phy.ntnu.edu.tw/ntnujava/index.php?action=dlattach;topic=831.0;attach=2550;image)

the reason i asked is i wonder how can i keep the translation in future releases of the same applet. Do i copy the languages files say Momentum1D2010web01_pkg back into the source folder D:\EJS_4.2.7_100314\EJS_4.2.7\workspace\source\users\sgeducation\lookang?


not to worry!

i found they here
D:\EJS_4.2.7_100314\EJS_4.2.7\workspace\export\users\sgeducation\lookang\Momentum1D2010web01_pkg
i copied the folder Momentum1D2010web01_pkg with the files
Momentum1D2010web01_en.properties
Momentum1D2010web01_pt.properties

into the ejs source folder say
D:\EJS_4.2.7_100314\EJS_4.2.7\workspace\source\users\sgeducation\lookang
create a folder Momentum1D2010web01_pkg and copied
Momentum1D2010web01_en.properties
Momentum1D2010web01_pt.properties inside

and created additional user files to Momentum1D2010web01_pkg the folder used to keep the translation.
and it is captured in any versions of Ejs now after i recompile them in Ejs.

Cool!


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: ahmedelshfie on May 17, 2010, 05:37:06 pm
The web based translator find the user's language code for utf-8 transfer.
You will have problem if you try to translate portuguese characters.
It should be fine if it was done by ahmed.

I test before a simulation i develop by my self is a projectile motion and after i finish translations
I publish in internet so work very well and no have any problem appear by pourtgas like i want
So i think will no have problems with other simulations porf  :)
This link for page that i test simulation  http://www.cneconline.com.br/cneconline/applets


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collisi
Post by: ahmedelshfie on May 17, 2010, 05:50:28 pm
added directly using the *.jar file the translation for portuguese pt. thanks to ahmed's original translation to brazilian portuguese brpt.
This is my first translated applet by ahmed which i helped to re-key in. It is ready for more translation to more languages, please help by downloading *.jar and key in and re attached as attachment, i will attribute the translators!

Thanks ahmed for translation to portuguese !! ;D ;D

it is on the first post now.
only available after u download the *jar file, not yet possible on the web deployed applets.


Oh, Prof Hwang, i didn't continue to use the web based translator because the  brazilian portuguese characters i keyed in were cut off.
for your info.

for example,
View.drawingFrame.title    = Colis = Colisão elastica e inelática

by the way, does anyone know where the files for the translation are kept in Ejs? i thought i saw before but i could not find it after unzip the folder of the *jar file.


Oh, Ahmed i also translated to english your copy of the applet. attached! enjoy! :D
Thank you prof Lookang and thanks for prof Hwang too for accept me translations simulations to portages version
I made download i think idea of prof Hwang very good idea that he want every simulation i publish by portages version
I add the original link by English in site that i will publish i see i very good idea prof lookang   :D


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on May 18, 2010, 08:30:35 am
hi ahmedelshfie

this file has the english and portuguese language packed inside, the version with your color scheme design.

u know how to make add english and portuguese to all your re-color simulations?

good luck!


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: ahmedelshfie on May 18, 2010, 09:41:30 am
Thank you prof Lookang  ;D


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on May 21, 2010, 12:22:20 pm
i managed to meet up with my school teacher friend and got some of the student feedback forms.
i key in the data (43) / ~200 forms, the data seems to suggest it is a meaningful practical lab made possible through this applet and planning from the teachers in that school RVHS.
(63) / ~200 as of 8sept2010




you can see the data (feedback) and come to your own conclusions whether it is meaningful to start using similar applets as practical lessons to give students the chance to conduct inquiry learning in student centered pedagogy.

Google Form which all can see, not edit
https://spreadsheets.google.com/ccc?key=0AjIvSg-TzZrZdGVoQzE5WlVWcU9FREJhaXBLYi1jZ1E&hl=en&pli=1

summary of results
https://spreadsheets.google.com/gform?key=0AjIvSg-TzZrZdGVoQzE5WlVWcU9FREJhaXBLYi1jZ1E&hl=en&pli=1&gridId=0#chart

[eye]

[/eye]


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on May 21, 2010, 12:59:39 pm
Grouping of would you want to attempt similar lessons for other topics in the future?

+ 37/43 plus points 86%
it is very interactive
dry to learn from lecture, need experience to understand
i would love to attend such lessons because it involves a higher degree of interaction between user and computer
it is interesting
help visualize and learn about the concepts
fun and interactive and can discuss with partners
easier to understand
simulation let us visualize the events and the hands-on activity boost interest
easier to understand with demo and actual calculations
more interesting way of learning allow us to enjoy learning
more enjoyable than normal lesson, due to the interactivity
interactive and effective in teaching concepts
keeps me awake and alert to pay attention to topic taught
enables us to do collaboration discussion
more interesting and enjoyable than lectures
less passive learning
such lessons promote collaborative learning
promote collaborative learning
challenged to make connections, when we do there is a great sense of satisfaction
very interesting
easier to learn about relationship between variables
simulation help understand topics, instead if just images on notes
interesting change from usual lesson
takes much less time, view accurately the theoretical outcomes
can watch effect of collisions in different situations
hands on activity more entertaining and will make lesson less dull therefore we can concentrate even better
interesting
these kinds of lesson force us to think critically. it makes us look at the results, analyze and then find the trend within, which is a really good way to learn independently. it also gives us confidence and a sense of accomplishment when the conclusions we arrive at are correct. my favorite :)
easier to understand than theory lessons
it lets me figure out the concepts rather than just listen and believing what is taught without understanding
the lesson is interesting and hands on
normally people would have to experience any physics concepts themselves through hands on to really remember concepts. Lectures on the other hand may not be effective since maybe what the lecturer is bringing through us is unclear, and thus practical lessons to learn concepts is a great learning deal
allow to explore the knowledge and content ourselves, interesting


- 6/43 negative points  14%
quite hard to learn through thus with the teacher does not teach and explain much about it
benefit more from just watching a clip
instructions are very confusing and even if we get the answers, we do not understand why it is that way
not clear about the learning points
the activity worksheet did not generate much thinking and concept understanding, just simply presents a set of values to copy to get the answers worksheet design issues??
not interesting




Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on May 21, 2010, 01:14:30 pm
is there anything you feel should be done to enhance the lesson?

- applet design issues
add sound effects done! 29May2010 effect of sound after collision http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=824.0
more sound effects added                my answer! can't add sound on perfectly elastic due to conservation of energy :)
program lacks instructions to what to start with. clearer indications and more organized layout is preferred       i can change the layout but i need to understand how to improve it, need concrete layout and design diagram, but good point
simply recording of results is rather monotonous. program designed as a game, thereby making it more interactive. done 26May2010 adding the game checker for auto assessment of learning thanks to http://www.compadre.org/osp/items/detail.cfm?ID=10000&S=7 One Dimensional Collision Model written by Andrew Duffy
at the end a table can be provided and it would provide us with the values. from there, we do analysis.   let me find out if it can and should be done, great suggestion!


- implementation issues beginning of lesson
short briefing before use applet
instruction should be more clear
explain basic concepts before carrying out activity
crash course in concepts of momentum and relevant calculations
go through basic theory
short introduction to the topic before the experiment, so as to give a better idea of what is going on.
we can also be taught some important points to pay attention to


- implementation issues during lesson
state the assumptions and give questions instead of just completing the table
tabulate less data strain on hands
too many reading to take for the table
give hints to think about what they have done and draw correct conclusions
more explanation for data collected to aid understanding
teacher provide some questions, then discuss in small groups, then discuss as a class.





Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on May 21, 2010, 01:18:36 pm
any other comments from students


instructors are very helpful :)    of course, 2 teachers in one lab plus i am a super teacher :)
i really thank you for spending time coming up with this program.you are really an educator who cares and dares to try new things. thanks! hope you can come up with even better programs so that they can empower students in physics subject.     just wanted to share this joy with Prof Hwang and others educators in this forum, keep doing what you are doing with learning with simulation (technology).


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on September 16, 2010, 10:32:33 pm
doing an upgrade


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on February 03, 2012, 01:09:23 am
another discussion on this simulation

> 1. I have tried the Java sim from your blog, can set velocity to 0.5 but not 0.2, 0.3 etc. Also, it will be better if users can directly type the values they want, instead of dragging the scale.
>  
Did u try to key input values in the input fields
I just tried seems 0.2 can be set.
Avoid the sliders for specific values.




> 2. you have a "paused at collide" function which is useful, is it possible to show the forces just as how you display the velocity vectors? Can show students forces acting on block A and B are the same according to NTL. From there, we can develop the concept : force of same magnitudes, same time during collision, Fx t, so change in momentum for block A and B ae the same, but in opposite direction. (I have attached a partially done worksheet, adapted from University of Washington using the inquiry approach)
>  
Seems like a good idea

> 3. In relation to pt 2, can we add a Force-time graph?
>  
But the force time graph is just a _|_ graph nothing much to see unless we redesign the model to be more like real life then can see a bit _|-|_ graph. Can u show a graph u have in mind ?

> 4. Can we input very large values for mass. e.g. a very small mass collide with a very large mass, just like we bounce a ball on the ground. Conversely, it will be good if we can show very large mass colliding with very small mass.
>  
Input field can accept any mass, don't use the slider

> 5. This is probably the hardest pt. Coefficient of restitution, e, is not covered in the syllabus. Students usually use u1, u2 and v1 or v2 to find the other final velocity. They do not need to care about the value of e and do not know how to calculate e anyway. It will be useful to students if we can allow them to input v1 or v2 such that they can check their tutorial answers, but of couse got to ensure that corresponding value for e is also calculated correctly.
>  
It is already possible.
Did u select the table check-box to key in values ?


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on February 03, 2012, 01:42:02 am
1. Think I will stick to the original Java Sim that RV uses.
Think my worksheet focus on constructing knowledge from NTL, then towards COM.
It should also test students on multiple intelligence and relating the momentum-time and force-time graph. (Please refer to attached pic for graphs)
 
i will try to add http://www.thephysicsfront.org/items/detail.cfm?ID=3969 into the current sim to achieve what u want

2. As for input of values for mass, u1 and u2, I can do it now. thanks.
 
nice


However, don't think i can input v1 or v2. The java sim calculates v1 and v2 together based on a certain value of e.

yes it cannot be done yet, the physics is not deterministic


But students don't know about e, so can we just let them input v1 or v2 and calculate the other, without showing e. (Note: in tutorials, when we give students a certain value of v1, we are already assuming a certain value for e)

here i disagree with the syllabus, the treatment of collision is inadequate to prepare physics students for university.
let me think how to solve this, maybe i release another sims just for v1 n v2 inputs

 
3. For the momentum-time graph, there is a vertical line at t=0. Looks like the momentum dropping from somewhere. Can we eradicate this?

yes, done



hi prof!
can allow file extension .docx ??
Dynamics Wksht_EJS.docx.
You cannot upload that type of file. The only allowed extensions are gif,jpg,mpg,pdf,png,txt,xml,java,html,jar,ip,avi,swf,zip,doc,mov,jpeg,htm,jqz,rar,trk,mp4,ejs,apk.


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on February 03, 2012, 03:00:18 pm
changes
added F vs t graphs
added  if (t>=tcollision&&t<=tcollision+dt){
F1 = mass1*(vx1-vtemp1)/dt;
F2 = mass2*(vx2-vtemp2)/dt;
totalF = F1+F2;
  }
added different way to make sound
if (elastic==true)
{
  sound=false;
}
else
{
Toolkit.getDefaultToolkit().beep();
//sound = true; // sound produced
//t_onsound = t;
}
added pause and diagram of F1 and F2

enjoy!


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on February 03, 2012, 03:26:31 pm
Question:
u really want a input field for v1 n v2?
that would mean a lot of possibilities,
e >1 super elastic
e=1 ok
0>e>1 ok
e =0 ok
e<0  impossible to happen

what computer responses are required for e>1 and e<0 ?
disallow?
a text message? "super elastic" or "impossible!,
re key v1 n v2"

any thoughts?

i would not be able to add on to the same simulation, i will have to release another version cos the codes need to be reprogrammed with v1 n v2 as inputs

Hi prof hwang!
i am at Radisson Hotel Ontario Airport http://aapt.org/Conferences/wm2012/hotelpage.cfm
2200 East Holt Boulevard
Ontario, California 91761
United States

but notice the forum still capture as 04:26:31 pm » posted from:SINGAPORE,SINGAPORE,SINGAPORE
for your info :)


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on February 16, 2012, 02:15:44 pm
discussion with teacher

1. Request to show the final velocity of the carts only after collision. Currently, when I input the initial velocities, the final velocities are shown immediately, even before I click play
 
ok,

2. Request to display magnitude of F1 and F2.  Currently, when use "pause" function, vector arrow of F1 and F2 are shown but not its magnitude. Furthermore, the Force vector is often too long and goes out of the screen. Students cannot compare its magnitude.dd

reduce the length
show number now //force
  s_F1 = " { F_1 } = "+double2String(F1,1000.);
  s_F2 = " { F_2 } = "+double2String(F2,1000.);

 
3. Enlarge or zoom in the time of collision. i.e. enlarge the width of the spike in F-t graph.
Rationale: during collision, the force acts on the carts over a period of time. During this time interval, at any instant, the force acting on the two carts must be equal and opposite. Wants to emphasize this pt to the students.

cannot be done, because of the very short time during collision happens only of a small fraction of dt.
can zoom in but the period of time is a small fraction of dt thus it draws like a triangle.


 
4. Related to pt 3, since the F-t graph now looks like a triangle, the force during collision is not constant. As such, the momentum-time graph must show a curve during collision.
 
Force acts for a very very short time, so it cannot be constant, it is a spike value.
so momentum is slope down or up depending on whether it is an decrease or increase of momentum.



5. What is "game"? in the Java Sim. What is the function of this?

game is an assessment of learning, where student can try to key in values to check whether they understood the concepts in COM and COKE during collision.


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on February 17, 2012, 09:37:14 am
discussion with teacher

For pt 3 &4, our purpose is to really focus on what happen during the collision. Upon collision, the colliding bodies undergo periods of deformation and then restoration, so the force during collision will not be constant. Nevertheless, at any instant during collision, the forces acting on body 1 and 2 will always be the same. This is a very important concept from NTL that we want to emphasize to students. Moreover, this is similar to the graph in TYS N04/3/2.
 
We hope you can help us change the time scale of the graph, so that we can amplify the time during collision.

For that TYS qns I mentioned, the F-t graph is a curve (which i think might be harder for programming)
I was thinking more of a triangle instead of a curve, and the inverted triangle that is of cos symmetrical. Add more frames/steps during the period of collision? In this case, it will be obvious to the users that any pt in time during the collision, the forces are always equal (one positive, one negative)

if it is a triangle, it is done
it zoom in, select data tool by right click and select the Ft graph

it is a triangle impulse, not a curve impulse, the concepts is still
the same, forces F1 n F2 are equal and opposite act on different
bodies.

the time scale cannot zoom in during collision, because the computer
model currently assumes instant re-bounce (idealistic), really touch
and go, no spring like deformation

to get a wave impulse like in TYS N04/3/2, i need to reprogram the
collision for all cases of collision e=0, 0 < e < 1, e=1 etc. which the
curve impulse is valid for  0 < e < 1, e=1 etc, but not for e=0 i think.
so it is rather complex.




Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on February 17, 2012, 02:00:55 pm
discussion with teacher

We are receptive of triangle impulse. in fact, we agree that the algorithm for curve is too complex.
The two triangles can indeed show F1 equal to F2 at the peaks of the two triangle impulse.
 
Only thing is if the triangle impulse is wider (maybe change the scale of the time-axis etc. ..i don't know...) then at any pt in time inside the triangle, we can show F1 will always be equal to F2. NTL always applies. This is the enduring understanding that we want to instill in our students.

we can get student to do a data analysis of the Ft graph
scale horizontal set to just before and just after the collision
as in my 2 pictures.

get the student to think about
0.60 s
0.601
0.602
0.603
.....

with these evidence data, they could conclude that the F1 = - F2 during collision, thus N1L is validated.


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on February 28, 2012, 12:23:53 pm
another discussion with another teacher



Is it possible to introduce the following changes to the simulation?
1.  remove the formula

in line with our 2nd multiple representation pedagogy and research, the formula is actually a form of symbolic representation that we speculate helps learners form a coherent mental model of this topic of momentum.
can keep please and use it?

 

2.  remove the hints

same as 1, can keep please and use it?
our research experience using this computer model suggests it could be useful to promote thinking about the problem of types of collision types


3.  can the final velocities appear only after the collision?

i think already done based on earlier request by AJC teacher

4.  remove change in font size

we speculate the size emphasis help learners focus on that is being modeled in that time

5.  a much larger difference in mass? (right now it's only 1 to 7 kg?) possible to key in any positive real number?

key in directly into the input fields, all computer models currently that lookang makes, can have or already has this user input features

6.  same for velocity?  The arrow length can be proportioned between the two velocities?

i believe it already is drawn proportionally and always pointing to the right consistent in convention to traditional pen paper solutions. please check?

7.  spell momentum instead of mom? Can also use p1 and p2 too.

i think can spell momentum, i try but please note the space constraints already inside existing model
i think can use p1 and p2 but it is better than m1*v1 or m1*u1 ?
i normally avoid using p1 as it could be confusing as p1 = m1*u1  when t < tcollision and p1 = m1*v1  when t > tcollision.
please think this through i should be able to but i need you to be sure :)


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on February 28, 2012, 12:33:06 pm
another good suggestion by teacher


Good idea, I try  no promises, I need to figure out the computational physics of this, in relation to what is already made.

“possible to make "explosion" case?

Before "explosion", one single mass to be keyed in (either moving or stationary)
After "explosion", 2 masses flying apart (students to key in ratio?)
Quantities to be calculated are final velocities, initial and final KE, initial and final momentum.



Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on March 05, 2012, 10:09:59 pm
work in progress


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on March 09, 2012, 10:29:13 pm
more request



The arrow length can be proportioned between the two velocities?
So if i want to key in v1 = 500 m/s, the space constraints wouldn't allow
>> it. So i wrote

done, it saturated








explosion:
>> M before explosion
>> U before explosion
>> Fraction of masses after explosion or m1 and m2
>>
>> To calculate:
>> Initial KE
>> Fraction of Final velocities
>> Fraction of Final KEs
>>
>> Formula:
>> MU = m1v1 + m2v2

not done, not sure if it is can be done


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on March 13, 2012, 02:24:20 pm
work in progress

teacher discussion.
1. The F-t and momentum-time graphs are not aligned. The end of the momentum change seems to be aligned with peak force
2. The velocity vector is incorrect. For e.g. 1 m/s is longer than 2 m/s.


1. consulting
2 fix bug of arrows and also added Math.abs() to force arrows always to the right


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on March 26, 2012, 11:55:31 am
after discussion with teachers

several request were made.


1. velocity convention to be direction left is negative while always showing magnitude to be consistent with this particular schools teaching practice.
done

2. bug fixed for tmax for the graph to show the tmax consistently

3. some text changes as explain by teacher in accordance to text used in A level now.
perfectly elastic == elastic
partial inelastic == inelastic
perfectly inelastic == perfectly inelastic


4. spring model for collision will be release in a different model as i want to keep this version with event handler.
watch out for that :)


Title: Re: Ejs open source java applet 1D collision carts Elastic and Inelastic Collision
Post by: lookang on March 26, 2012, 04:05:27 pm
more changes
set x1 = - 0.25
set x2 =  0.25

the spring force collision model need a longer time to saturate to the ideal values.

enjoy!