Ejs Open Source Electric Field & Potential of 2 Charged Particles Java Applet

[lookang]

Ejs Open Source Electric Field & Potential of 2 Charged Particles Java Applet
Ejs Open Source Electric Field & Potential of 2 Charged Particles Java Applet by Professor Andrew Duffy, remixed by lookang

Ejs open Source Electric Field and Potential in a One-Dimensional of 2 Charged Particles Java Applet
In this simulation, you can investigate the electric field and the electric potential at various positions along a line, when there are either one or two charged particles on that line. In particular, you can explore the connection between the field and the potential.
The field and potential are represented in two ways. First, the table at the bottom shows the values of the electric field and electric potential at the position of the point charge. Values are given for the field and potential due to each charged particle individually, as well the net values.
The second way to represent the field and potential is graphically. You can look at both the graph of the electric field as a function of position, as well as the graph of the electric potential as a function of position. The graphs are probably most helpful in determining how field and potential are connected.
In addition, the arrows attached to the movable test charge show the field at the position of the test charge from the two charged particles.

Activities
This is challenging, but see if you can determine how field and potential are connected to one another. A good place to start is by turning on both of the charged particles, and giving them the same sign. This gives a place between the two particles where the net electric field is zero. At that same point, what is going on with the potential? Can you use that information to help you figure out how field and potential are related to one another?

Embed a running copy of this simulation
<applet code='users.sgeducation.lookang.EField_and_Potential_1D_v2wee_pkg.EField_and_Potential_1D_v2weeApplet.class' archive='http://www.phy.ntnu.edu.tw/ntnujava/ejsuser/14019/ejs_EField_and_Potential_1D_v2wee.jar' name='EField_and_Potential_1D_v2wee6989' id='EField_and_Potential_1D_v2wee6989' width='750' height='600' mayscript=true><param name='draggable' value='true'></applet>
Embed a running copy link(show simulation in a popuped window)
<a href='http://www.phy.ntnu.edu.tw/ntnujava/msg.php?smfejs=6989' target='smfejs'>Run simulation</a>

Full screen applet or 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!

[lookang]

Java Applet.
I did not make this applet, Andrew Duffy http://physics.bu.edu/~duffy/classroom.html is the creator! i only remixed it. It is exactly what we need in the Singapore syllabus as well. nice!
mirror here as well http://66.7.205.91/~lookangc/index.php?topic=1052.msg2072#msg2072

changes made: was at the airport after 2010 AAPT Summer Meeting in Portland, Oregon, at PDX airport from 11 pm 21July to 6 am 22July, made used of the time to customized this applet.
1 redesign the look and feel to be all buttons and slider on the bottom panel
2 color scheme for red is + charges, blue (64,64,250) for - charges even visible for the slider now
3 resized to 600,600 for http://sgeducation.blogspot.com/ http://sgeducation.blogspot.com/2010/07/ejs-open-source-electric-field.html
4 added forces F1 an F2 when show2&&testc==false
5 added symbolic representation of Enet and Vnet
29Sept2010
6 added KE = 0.5*m*v^2 ; PE = q*Vnet; TE = KE+PE; due to question by leeyiren http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=1965.new#new
03 August 2011
made some changes add input field to support the sliders
rearrange the check box
add a step () button
add color codes for the test charge as well, red = +, blue = - grey = 0
add range of view if test change move outside current xmin and xmax using the codes

Code:

if ( xtest < xmin ) xmin = xmin*1.2;
if ( xtest > xmax ) xmax = xmax*1.2;

make the graphs to plot to go to xmin and xmax instead of the older -6 and 6 range