# NTNUJAVA Virtual Physics Laboratory

## JDK1.0.2 simulations (1996-2001) => Electromagnetics => Topic started by: Fu-Kwun Hwang on March 08, 2004, 08:58:59 am

Title: Trajectory of a test charge in electric field
Post by: Fu-Kwun Hwang on March 08, 2004, 08:58:59 am

There are two fixed charge (red +/ blue negative) create an electric field around the test charge.
If the initial velocity of test charge is zero. What is the trajectory of the test charge?
Will it following the electric field line?

You can test your answer in the following post. Play with the simulation!
You can drag test change to another position and try it again ...
Title: topic97
Post by: Fu-Kwun Hwang on March 08, 2004, 09:01:12 am

Title: topic97
Post by: on March 26, 2004, 06:39:12 am
hello my name is mr burnsi belive you have a message 4 me
ok mr burns whats ur first name ?
i dont know
Title: topic97
Post by: on September 15, 2004, 09:12:13 pm
I do not understand why the charge would not follow the direction of the field. It is the only one, it can not have an influence on electric field he fiels. Plus the initial velocity is zero. Or is it something else ....

Dejan

:shock:
Title: Charge particle motion
Post by: Fu-Kwun Hwang on September 16, 2004, 08:29:30 am
The tangential of the field line is the direction of the electric field.
From Newton's Law: The acceleration of the charge particle is propotional to the electric force.
So the acceleration of the charge is in the direction of the electric field.
The acceleration of the particle tell us how the velocity change with time.

The tangential of the trajectory is the direction of the velocity ( Not the change of velocity: acceleration).
When the velocity of the charge particle is zero, the direction of the velocity is the same as the direction of the acceleration. However, when the velocity of the charge is not zero, the electric field line provide the direction of acceleration (not the direction of the velocity). So the electric field line did not match with the  trajectory of the particle.
Title: topic97
Post by: paco on May 20, 2006, 06:03:22 am
[color=darkred:6e8b4053b2][/color:6e8b4053b2]
Title: topic97
Post by: sunilbalani on August 26, 2006, 02:50:40 pm
great work what will be the path if there is an intial velocity can that be worked out . can we down load applet to help students for offline usage.bye sunil balani M.E,MBA
Title: Re: Trajectory of a test charge in electric field
Post by: metwally on March 20, 2007, 12:30:45 pm
<IMG src=/demolab/phpBB/pics/fieldLine.jpg>
There are two fixed charge (red +/ blue negative) create an electric field around the test charge.
If the initial velocity of test charge is zero. What is the trajectory of the test charge?
Will it following the electric field line?

You can test your answer in the following post. Play with the simulation!
You can drag test change to another position and try it again ...

Title: Re: Trajectory of a test charge in electric field
Post by: Fu-Kwun Hwang on March 25, 2007, 12:45:16 pm

You should be able to download it now. It was created with physlet library (http://webphysics.davidson.edu/Applets/Applets.html).
Title: Re: Trajectory of a test charge in electric field
Post by: flg22 on September 04, 2008, 01:52:04 pm
Could you please email me the source code?  Thank you.
Title: Re: Trajectory of a test charge in electric field
Post by: Fu-Kwun Hwang on September 04, 2008, 05:51:10 pm
The above simulation was created with physlet (http://webphysics.davidson.edu/Applets/Applets.html). You need to ask original author for the source code.
Title: Re: Trajectory of a test charge in electric field
Post by: jeff_forssell on September 05, 2008, 07:36:22 pm
I don't think you will be able to get the source code for the physlets applets themselves. But they are free to use and you can make changes in a simulation like this one by going into the javascript code in the HTML page and changing it to fit your needs. It's probably all the "source code" you need. See the Physlets homepage for more info.
Title: Re: Trajectory of a test charge in electric field
Post by: Fu-Kwun Hwang on January 12, 2010, 12:20:34 am
However, you can download the jar file and the html page from the second message.
Just click "get files for offline use" button!