Author Topic: Ejs open source converging & diverging Lens object image high school java applet  (Read 64983 times)

lookang

  • Moderator
  • Hero Member
  • *****
  • Posts: 1772
  • http://weelookang.blogspot.com
    • lookang web
more teacher feedback
made a tinyurl for the students to access this applet more quickly
http://tinyurl.com/rgslens

I realized the virtual rays are still not "dotted" (or fainted) correctly.
The rays exiting the object should be solid ray (your red ray exiting object is fainted).
The rays entering the object from the image should be dotted and doesn't need an arrow head.

cheers!

need to understand what the teacher means
The rays exiting the object should be solid ray (your red ray exiting object is fainted).
The rays entering the object from the image should be dotted and doesn't need an arrow head.

lookang

  • Moderator
  • Hero Member
  • *****
  • Posts: 1772
  • http://weelookang.blogspot.com
    • lookang web
added more inputs from teacher

dotted lines when the image is virtual and remove the arrows

managed to do corrected i hope for the green principal ray.
need to take a break for a while.

fixed the red lines in second attachment ejs_ThinLenModel01.zip
« Last Edit: September 20, 2012, 04:46:27 pm by lookang »

engrg1

  • Jr. Member
  • **
  • Posts: 69
Looking at the old simulation remind me of the times when I am using Prof Huang's lens applet to teach my students about drawing ray diagram :-) That is like 4 years ago.

lookang

  • Moderator
  • Hero Member
  • *****
  • Posts: 1772
  • http://weelookang.blogspot.com
    • lookang web
Looking at the old simulation remind me of the times when I am using Prof Huang's lens applet to teach my students about drawing ray diagram :-) That is like 4 years ago.
the older applet is here
www.phy.ntnu.edu.tw/ntnujava/index.php?topic=48

this a new version made in EJS

completed the dotted lines requested by teachers

teacher also asked
"Also regarding the object at focal length, I think there should be no
image so is it ok to display v = infinity?
Although I know in theory, 1/f = 1/u + 1/v but is it still valid when
there is no image?"

but i check there is no image
« Last Edit: September 20, 2012, 04:54:59 pm by lookang »

lookang

  • Moderator
  • Hero Member
  • *****
  • Posts: 1772
  • http://weelookang.blogspot.com
    • lookang web
more feedback!

 1) Wow! Thanks bro you are truly amazing! :))
The blue ray is not quite correct. I've attached a picture for your reference.

seems to have fix it now

2) u, h and F are in steps of 10. Could you change them to steps of 5.

done


3) Just found 2 new bug.
a) When F = 0, there is no lens.
Maybe for the slider, can skip F=0. If they want to key in, let them be.

change the value turn to 5 instead of 0 when 0 is selected

b) When F = 40, u = -10, the green ray is too short (doesn't cut F)


done! made it always reach the xminimum and xmaximum

enjoy!
« Last Edit: October 01, 2012, 05:36:34 pm by lookang »