Comments/Suggestions in 1998/1997
Date: Wed, 9 Dec 1998 16:07:30 -0500
From: louise heaven <email@example.com>
To: Fu-Kwan Hwang <firstname.lastname@example.org>
Thank you very much Mr Hwang, for your reply to my plea about the pendulum.
I was very pleasently surprized to find you had done so.
I would also like to say that you have a very good web page and i shall
look there first when i am researching physics.
Subject: Re: thanks!
Date: Sat, 05 Dec 1998 18:52:08 -0500
From: dgoodwin <email@example.com>
To: Fu-Kwun Hwang <firstname.lastname@example.org>
Thanks so much for taking the time to send me the http for circular
ang. mo. I really appreciate it. It's great stuff.
Bye for now. Dave G.
Fu-Kwun Hwang wrote:
> I am really sorry for the late reply. This message was misplaced.
> There are two java applets related to the angular
> Kepler motion: http://www.phy.ntnu.edu.tw/java/Kepker/Kepler.html
> and circular motion
> dgoodwin wrote:
> > Do you have any applets on angular momentum??
> > Fu-Kwun Hwang wrote:
> > > dgoodwin wrote:
> > >
> > > > We were reviewing vector addition this evening at a study session.
> > > > Someone asked about help from the internet, so we searched
> > > > to find your page. There were a few "ah-ha's" when the
> > > > the parallelogram method for adding vectors so clearly.
> > >
> > > I am very happy to know that you are enjoy the java applets.
> > > suggestions you might have about my java applets will be highly
> > > appreciated! Or , if you would like to have java applet one any
> > > related to physics,
> > > Just send me a note! Enjoy the virtual physics laboratory!
Subject: Note of Appreciation
Date: Tue, 17 Nov 1998 13:12:15 AST4
From: "GEARY MACMILLAN" <GMACMILL@dhs.ednet.ns.ca>
Organization: Dartmouth High School
Dear Fu-Kwan Hwang,
I am a physics teacher at Dartmouth High School
Nova Scotia Canada. I discovered your applets a couple of weeks
and am still exploring them. They are an invaluable resource
my students and for use in teaching in my classroom. I have used
so far and built my lesson around it...a lesson I had taught before
but it added that extra pzazz and interest for my students. We
using the reaction time applet. I showed them how to do the
calculations using the motion equations and then we gathered data for
stopping distances using the applet. They were also thrilled
the internet used in such a meaningful way...they have become
skeptical of the junk out there.
Please accept my sincere thanks for the excellent
quality of the
applets and I hope your work is able to continue.
Geary Mac Millan
Science Dept Head
Dartmouth High School
Date: Tue, 10 Nov 1998 23:00:38 -0500
From: "Mark C. Barnett" <email@example.com>
fantastic web page. i'm doing a report on wave division multiplexing
found your web site very useful and easy to use. thanks for the
Subject: Links2Go Key Resource Award
Date: Mon, 9 Nov 1998 14:50:44 -0500
Congratulations! Your page:
has been selected to receive a Links2Go Key Resource award in the
Java Applets topic!
The Links2Go Key Resource award is both exclusive and objective. Fewer
than one page in one thousand will ever be selected for
inclusion. Further, unlike most awards that rely on the subjective
opinion of "experts," many of whom have only looked at tens or
hundreds of thousands of pages in bestowing their awards, the Links2Go
Key Resource award is completely objective and is based on an analysis
of millions of web pages. During the course of our analysis, we
identify which links are most representative of each of the thousands
of topics in Links2Go, based on how actual page authors, like
yourself, index and organize links on their pages. In fact, the Key
Resource award is so exclusive, even we don't qualify for it (yet ;)!
to find out more about this award, and to download graphics if you
to display this award on your page.
Once again, congratulations on your award!
P.S. If you are not the author or maintainer of this page, please accept
our appologies. We would appreciate it if you would forward this email
to the appropriate person.
Subject: java applets
Date: Sat, 31 Oct 1998 21:30:46 -0500
From: Cliff Sampson <firstname.lastname@example.org>
Many thanks for the java applets that you so kindly sent me. The
teachers in Singapore were very impressed with them and I am sure that
your mirror site at the Singapore Chinese girl school must be over
worked. The implimentation of these java
applets together with others that I have obtained from programmers
around the world and my successful integration of computer based
technology into the science curriculum has resulted in my nomination
the college for the Prime Minister's Award for Teaching Excellence
is indeed an honour for me and I am required to present some of my
which obviously includes some of your java applets. My work is purely
pedagogical in nature and focusses primarily on use of technology as
effective teaching tool. It also involves how various systems and
strategies can be adapted to fit various learning styles.
I would therfore like your formal permission to use these applets and
submit copies of them ( with full formal acknowledgement of your
authorship) in support of my nomination.
Many thanks for your help and support.
Clifford Sampson PhD
540 Lakeshore Road
Ontario, L6K 3P1
Date: Wed, 21 Oct 1998 21:21:49 -0400
From: dgoodwin <email@example.com>
We were reviewing vector addition this evening at a study session.
Someone asked about help from the internet, so we searched and happened
to find your page. There were a few "ah-ha's" when the program
the parallelogram method for adding vectors so clearly. Thanks.
Date: Sun, 11 Oct 1998 15:30:39 -0400
From: "yoadrienne" <firstname.lastname@example.org>
I just wanted to write in order to thank you
for the lovely sites you have
online regarding virtual physics. I teach 12th grade/advanced
physics in the
USA and have assigned your virtual labs to my students to do as extra
credit at home.
We have all been truly delighted by the work you have done.
Thank you again and best wishes!
Apex High School
P.S. The kids also wanted me to mention that they really like
the way you
Subject: DOPPLER EFFECT
Date: Fri, 09 Oct 1998 09:43:01 PDT
From: "Michael Breen" <email@example.com>
Wow, I've been teaching 17 years and finally I can show students doppler
effect and sonic boom. Thanks
Subject: Physics of Pool
Date: Wed, 07 Oct 1998 14:13:44 -0400
From: Adam Lapatin <firstname.lastname@example.org>
Hi, I just played around with your java applet for billiards and I was
wondering if you know of any good books and/or websites about the
physics of pool. Any information you have about the subject would
be extremely helpful ... if you haven't guesses I'm writing a report
the physics of pool.
Date: Thu, 1 Oct 1998 22:50:42 +0800
From: "HUI Man-yan Mark" <email@example.com>
I am a high school physics teacher in Hong Kong. I happened to
visit your site and found that your simulation
of physics phenomena and concepts are extremely useful. I intend
to use them for my lessons. I anticipate that
my students will enjoy them very much. Thanks for your great
work for a school teacher like me.
Subject: (pas d'objet)
Date: Wed, 23 Sep 1998 11:46:22 +0200
From: croussel <firstname.lastname@example.org>
Very interesting program for my studients
Subject: java applet on shadow/image
Date: 15 Sep 1998 11:16:06 EDT
Our fifth grade science teachers love your applet on color mixing and
images. Please feel free to create activities that are appropriate
the elementary level.....they are highly needed and greatly appreciated
(especially on magnetism and electricity). Thanks again.
Subject: Your Page
Date: Mon, 14 Sep 1998 07:30:04 -0700
From: "Maurice O'Brian (Manpower)" <email@example.com>
To: "'firstname.lastname@example.org'" <email@example.com>
I must say I was impressed with your entry on the web, I found it very
helpful in inderstanding relativity.
Maurice O' Brien
Subject: Brownian motion
Date: Sat, 5 Sep 1998 10:18:45 +0100
From: "Peter Mussard" <firstname.lastname@example.org>
The animation is good, but the text 'Green dots are velocity distribution
molecules' doesn't make sense.
Subject: You physics java applets
Date: Fri, 4 Sep 1998 23:28:37 +0100
From: "Peter Mussard" <email@example.com>
Subject: double-slit applet
Date: Tue, 25 Aug 1998 14:45:37 -0400 (EDT)
From: "James Bo Begole" <firstname.lastname@example.org>
Reply-To: "James `Bo' Begole" <email@example.com>
I liked to older version of the double slit applet better. The
on the old one was much easier to use, although it was slower to run.
can't map the frequency to a color in my head. Can you put up
a link to
your old version?
Why am I interested in your applet? My interest stems from our
collaborative learning systems. I have a system called Flexible JAMM
Applets Made Multiuser) that allows the shared use of single-user applets,
such as yours. Do you mind if we use the old version to test
difficult it will be for a developer to make an applet that can be
Flexible JAMM: http://simon.cs.vt.edu/jamm
Subject: learning from you
Date: Mon, 24 Aug 1998 20:47:51 +0800
From: Edmund J A Ang <firstname.lastname@example.org>
I would like to learn from you. How did you write the animated
programmes e.g. vernier calipers. Very interesting.
teacher Edmund ang
Subject: Thanks for great BioSavart
Date: Mon, 24 Aug 1998 22:16:57 -0700
From: "Sunpainter" <email@example.com>
I was looking for something on the shape of circuit for very small circuit
trying to predict some electromagnetic field changes in the circuit.
I will be using very, very small current.
Your simulation was incredibly, wonderfully helpful!
If I had to do all the math for each current change, it would have taken
Now I have my figures. THANK YOU THANK YOU!
It is for a strange little generator I am building.
K. Hodge Southern California
Subject: Conservation of Linear Momentum
Date: Tue, 28 Jul 1998 09:14:28 +0800
From: Lim Ai Phing <firstname.lastname@example.org>
I'm a physics teacher presently teaching my students dynamics.
Your collision java applet is really good, I'll ask my students to take
a look here!!
But can I suggest that the colour of the numbers be changed
because yellow doesn't show up much against a gray background?
ubject: Your applets
Date: Fri, 24 Jul 1998 13:13:16 -0400
From: email@example.com (Mike Diegel)
My friend and I had been discussing what a sonic boom is
and I was trying to describe how the sound waves come together to make
We came across your web page at
and used the applet. We thought it was a fantastic illustration of what
a sonic boom is,
and we just wanted to let you know that your work was appreciated.
Thanks for the help.
Date: Sat, 04 Jul 1998 11:57:20 -0700
From: Daniel Murphy <firstname.lastname@example.org>
I'm a student at Olympic College in Bremerton, Washington currently enrolled
in a physics class.
We are studying vectors, freefall, velocity/acceleration and projectile
Your web page is great!
I think the answer to the question of case one about the green circle is
the arc of zero vertical velocity.
When the object reaches zero velocity, acceleration remains a constant
9.8 m/s(sq) downward.
Subject: Enjoyed your supersonic applet
Date: Mon, 29 Jun 1998 15:30:54 EDT
I enjoyed studying your applet.
I have taken the liberty of making some minor wording changes so that your
description will be more grammatically correct.
I wish I were multilingual as you are! ;-)
The location of supersonic airplane.
If an airplane is flying faster than the speed of sound, it will produce
a sonic boom or shock wave.
As shown in the right figure, consider an airplane which is flying from
A toward B.
A listener is located at C. The sound generated at A travels toward C along
the path AC.
The listener hears the sound as the airplane flys toward point B.
( AB > AC ) DC is the path of the sound generated at D to the listener.
The airplane speed is V and the sound speed is Vs.
If AC/Vs > AD/V + DC/Vs [Isn't it unlikely that the shorter path will take
a longer time?],
then the sound generated at point D will arrive earlier than sound generated
at point A! Funny!
You hear something which happened later and then hear something which happened
What will you hear if a supersonic airplane flying over you?
Do you know where is the airplane when you hear it?
Can you point out the direction of the airplane just from hearing the sound?
This java applet let you play with such situation.
Press Start to start the animation. A listener is represented by an ear!
You can press the left mouse button and drag it within the screen to change
location of the listener.
The program draws sound wave paths to the listener.
The animation will be suspended when the sonic boom arrives at the listener.
Click the right mouse button to continue. The color of the paths changes
The order in which the sound paths arrive at the listener are shown also.
You can change the ratio of airplane speed of airplane to sound speed and
see the difference.
Subject: Great jobs!
Date: Sun, 14 Jun 1998 17:37:43 +0800
From: "Robinson Wang" <email@example.com>
Dear Mr. Hwang,
Hello! I am a student of the National Tsing Hua University(NTHU).
Maybe you've heard that the Material Science Engineering which is my major.
I'd like to appreciate the great jobs you've done.
At first, I come to this website because of my final-term physical report.
However, when I view the first exam, I can't help finishing all items in
Well, that's all what I want to say about this special work.
Have you a happy time in teaching.
Your sincerely, Robinson Wang '98.6.14
Subject: Web Site
Date: Mon, 8 Jun 1998 18:11:12 EDT
Hi! I'm a physics teacher in Blantyre High School in Scotland
and I've just discovered your Physics demos site.
When I return to school tomorrow I'll be directing my class to your site
Well done and thank you...
I'll be a regular visitor from now on.
Subject: problems with cyclotron java applet
Date: Thu, 4 Jun 1998 19:37:38 +0200
From: "Pietro Diviacco" <firstname.lastname@example.org>
My name is Pietro Diviacco. I am an Italian surgeon and live and work in
I tried to play Your applet "Cyclotron" but there was some problems.
Some of the images (*.gif 7 and 14) were not available and the applet was
In any case Your applets are very good and interesting (the working ones,
Thank You in advance for fixing the problems.
E-mail address: email@example.com
Date: Sun, 03 May 1998 12:47:55 -0600
From: The Lahrs <JohnJan@lahr.org>
I love your thin lens page: http://www.phy.nau.edu/~layton/JavaApps/thinlens/lens_e.htm
What a great use of Java!
I use Netscape, by the way, and the applet worked just fine and was very
I've been trying to figure out why a glass rod creates an inverted (about
one axis) virtual image.
Do you have an applet for a thick lens, or just a ray diagram that would
show this effect?
Is the thinlens.java code still available? The link was not working when
It would be interesting to develop something like this for seismic waves.
I'm a seismologist now, but my first love is physics,
which was my undergraduate major at Rensselaer Polytechnic Institute.
Thanks again for providing the world this great applet.
John C. Lahr
-- * John C. and Jan H. Lahr * *
JohnJan@lahr.org * *
914 10th Street * *
Golden, Colorado 80401 * *
(303) 215-9913 * *
http://www.lahr.org/john-jan * *
Date: Sun, 03 May 1998 15:39:11 -0600
From: The Lahrs <JohnJan@lahr.org>
I just figured out that the inverted image is not virtual but real,
so everything makes sense now.
Keep up the good work.
John C. Lahr
Subject: (no subject)
Date: Wed, 29 Apr 1998 22:13:08 -0500
From: Dion Sanchez <firstname.lastname@example.org>
I want to thank you for this page, it has helped me visualize what a text
book could not.
I have been looking for something like this for a long time.
great stuff thanks. dion
Subject: Java 動畫
Date: Mon, 27 Apr 1998 18:44:50 -0700 (PDT)
From: Dan Murray <email@example.com>
也發現了國立 台灣師範大學的物理系的網頁﹐所以發現了你的許多 Java 動畫。
直到 現在﹐我沒有意識了物理教師創造了那麼許多 Java 動畫。
但是﹐你供 應更多消息是適當。我的電腦是 Windows 3.1 的 PC 。
即使我使用比 較新近的 Netscape （就是 3.05）還不可以看見 Java 動畫。
最低的 電腦需要是 Windows 95。或許你可以給人講解﹐所以阻止挫敗。
我們 有 Windows 3.1 的人應該知道﹐ 惟有看見 Java 動畫的方法大概是買 新電腦。
可惜﹐因為我是物理教授﹐無奈繼續使用我的舊電腦﹗ Dan Murray 謹上
Subject: Refraction Applet
Date: Thu, 23 Apr 1998 10:14:02 -0400
From: Sandee Coats-Haan <LA_COATSHAA@PO.SWOCA.OHIO.GOV>
To: hwang <firstname.lastname@example.org>
Is there any way to change the velocity vector and/or the medium thickness
on your refraction applet if you don't have a two button mouse?
Sandee (Lakota East High School Physics)
P.S. -- you have an incredible site
Date: Fri, 03 Apr 1998 16:16:37 -0600
From: Kelly <email@example.com>
Mr. Hwang, I want to say that your virtual lab was unbelievably helpful
I attend the university of wisconsin-madison and I was having problems
with optics concepts.
I went under the internet and searched under lens and mirrors and fell
upon your lab.
I am very grateful. I was a little upset last night when I wanted to access
the lens mirror applet,
because I couldn't find it.
I guess even the virtual labs have hours of availability.
I guess that's my only suggestion,
which isn't a very necessary one to attend to when most of us can access
it during the day.
Thanks again, Chris firstname.lastname@example.org
Subject: Can I add a counter to the mirror site?
Date: Tue, 24 Mar 1998 19:02:33 +0800
From: "tanghb" <email@example.com>
Dear Mr. Hwang,
When I meet the physics teachers of the other schools in Singapore,
they give good comments about the mirror site of Virtual Physics Laboratory.
I think your Java Applets are popular in Singapore.
I am therefore interested to know how many people come to visit Virtual
and use your Java applets everyday.
Mr. Hwang, can I add a counter on the contents page?
If so, please let me know.
Tang Hung Bun
Singapore Chinese Girls' School
Subject: I saw a Polarized Rainbow!
Date: Sat, 14 Mar 1998 01:18:24 -0800
From: Neal Rasmussen <firstname.lastname@example.org>
I am, as far as I know, the first to see a "Polarized Rainbow"!
I think we should name this phenomona the "Rasmussen-Wang Rainbow". :-)
I am a tornado chaser for 20 years. About 4 years ago I was driving through
a McDonald's drive thru.
As it was just after a pretty good storm, I had mys polarized yellow tinted
flip-up sunglasses on.
Low and behold I almost dropped my cigarette into my lap.
There off in the east was a double rainbow!
Not the kind I've seen dozens of times where the second one is reveresed
and much outside the primary,
but this was immediatly INSIDE the primary!
Gaping with my mouth open and people behind me honking,
I flipped my flip-ups up and the second inner one went away!
I must have sat there for 2 minutes flipping my sunglasses.
The colors were NOT reversed and it looked like one continuous double wide
with two complete sets of colors.
I ruled out that the flip-ups where giving double vision as I looked at
lights the next day,
streetlights headlights, etc. and no doubles!
Can this possibly be? Could a source of polarized light be at a different
perhaps the sun shining through a cirrus cloud or noctelucent (sp).
Neal Rasmussen email@example.com
Subject: Thank you for the applet!
Date: Tue, 10 Mar 1998 10:34:26 +0100
From: Uwe Gaertitz <firstname.lastname@example.org>
To: "'email@example.com'" <firstname.lastname@example.org>
your applet works fine, thanks a lot.
We want to use it offline, for non-commercial demonstration.
I've mentioned you and made references to your site at this local page,
1. One goal is to maximize/minimize :-)
the flow. But it's so easy, with setting velocity and acceleration to max(min),
2. It would be fine to see the flow rate in an extra text field,
cause this is the much interesting output (for me).
3. Perhaps, a "history" of the last flow rates (then you can better see,
whether you have success in maximizing flow rate or not).
Could be a simple text table (over a time intervall), or a graph.
Subject: Your Doppler effect applet
Date: Sun, 8 Mar 1998 22:39:05 -0600
From: "Michael Vershinin" <email@example.com>
Your applet is pretty neat, but since you asked for suggestions...
1) I would not allow the user to set a negative wavelength.
2) If negative source speed is chosen, your source runs off the edge of
3) Negative wave speed is a bit awkward, since your source is actually
Date: Mon, 02 Mar 1998 13:32:38 +1100
From: masukor <firstname.lastname@example.org>
Hi, been to your physics lab. great stuff.
I teach physics at a junior college here in australia.
I certainly will make more visit to your site. bye.
Subject: java applets
Date: Sun, 01 Mar 1998 01:45:54 -0500
From: Clifford Sampson <email@example.com>
Dear Mr Hwang
I have found your java applets especially those on waves and optics to
be particularly facinating and informative.
So much so that I have begun to use them extensively for my grade 11 physics
at Appleby College in Oakville, Ontario, Canada. ...
Subject: Publishing Your Applets
Date: Tue, 17 Feb 1998 18:38:33 -0600
From: Taha Mzoughi <firstname.lastname@example.org>
Dear Professor Fu-Kwun Hwang
My name is Taha Mzoughi and I am an assistant professor of Physics at
Mississippi State University. I am currently compiling a library of Web-based
simulations and animations for a CD-ROM to accompany the forthcoming third
edition of Jones and Childers' CONTEMPORARY COLLEGE PHYSICS book. The library
will supplement software developed for the book by McGraw-Hill publishing.
The intent is for me to write an HTML page including a link to the selected
web resource along with credit to the author and text relating the animation/simulation
to the book content. In some cases, we might need to include operation
instructions. To reduce problems due to web traffic and to changes in web
addresses we prefer to include a copy of the actual animation/simulation
on the CD.
As a bound-in supplement to the book, the CD is intended to provide
the student with increased resources and a pathway to the resources available
on the Web without augmenting the cost of the book. We are mainly interested
in material that students can access for free on the Web. Credit to authors,
links to their sites, and any other material that we (or you) feel is needed
will be provided. I particularly like some of the simulation/animations/applets
you have developed and think that they are excellent candidates for the
library. The applets I am seeking permission for are at the following URLs:
hrough this email, I am formally asking you for permission to include
your simulation/animations/applets in the Contemporary College Physics
CD. If you accept this offer, McGraw Hill Publishing will send you a printed
version of the agreement. Obviously, to include your software in the CD,
we need assurances that you have full rights on all of its content. If
you are not the appropriate person to contact for permission, please let
me know whom to contact. Agreeing to include your simulation/animations/applets
in the CD will give McGraw Hill Publishing a NONEXCLUSIVE right to distribute
the software free of charge with the book.
I believe your simulation/animations/applets to be an excellent educational
tool and I would like to help get more students to take full advantage
of it. I am looking forward to the possibility of working with you on this
Please note that the publishing schedule is tight and I need your reply
ASAP. You may contact me at email@example.com (phone 601-325-2923)
or contact McGraw Hill Publishing directly by sending email to David Dietz
at firstname.lastname@example.org. Please include your "snail mail" address
in your reply.
We request permission to use the material in Jones/Childers third edition
and subsequent editions of that book (this is standard for excerpted material),
but not in other books. The permission letters reads:
We request your permission to include the following material on the
bound-in CD-ROM in this and all subsequent editions of the book, including
versions made by nonprofit organizations for use of blind or physically
handicapped persons (and in all foreign language translations and other
derivative works), for distribution throughout the world.
[Taha Mzoughi] I hope that this is fine with you. Your Applets are great
and students and teachers will greatly benefit from having them readily
available. I have made a presentation Friday to about 60 teachers from
around here. I showed some of your applets and they loved them. Most of
the teachers still don't have internet access readily available. Remember
also that you are retaining the right to publishing the applets elsewhere.
***P.S. 已經同意 加入下一版隨課本所附光碟中。
Subject: Physics Java Applets
Date: Sun, 15 Feb 1998 15:37:15 +0800
From: Stephen Chin <email@example.com>
Dear Sir, I'm also a Physics teacher, O level, and I am interested and
by the Java Applets you have created..... they are really good.....
I find them very useful for teaching and demonstrating certain concepts
I am wondering how do you write a Java Applet....
I have the Java Programmer Kit downloaded from Sun.... but don;t know how
to use it.....
Thanks in advance.
-- If we wait long enough we may reap the best harvest....
Subject: Java and Physics
Date: Sun, 15 Feb 1998 09:15:22 +0100
I am a professor of physics at the Royal Institute of Technologu in StockholmSweden.
We do teach Java for programming in Science and I came across your web
Although we do teach Java for Ph.D. students I think there is something
that could be learnt
from your beautiful pages. Maybe we will also extend the course to MS levels.
The problem is that we are in physics and Java should be taught by the
CS dept, but will they do it our way?
We may try to suggest a course and then some of your web pages could be
very useful to the students.
I would therefore like to ask you about your plans etc.
I would hate to have made refs to your pages and then they would disappear
one day, smile.
Also, you may have some new ones in mind?
I think something with the uncertainty principle would be very useful.
Have you ever considered this?
I am very open for any form of collaboration on this future teaching project.
You can find examples of the present course on the web.
We plan some lecture notes and I hope I can make ref/use some of your examples?
Looking forward hearing from you
// Thomas Lindblad
Date: Thu, 12 Feb 1998 16:57:50 -0600
From: Taha Mzoughi <mzoughi@Ra.MsState.Edu>
Organization: Mississippi State University
Dear Professor Fu-Kwun Hwang:
This is the first of two emails I will be sending you.
I have been familiar with your work for about a year now. To say the list,
it is impressive.
I am an assistant professor of physics at MS State University and I try
to use the Web for instruction.
The URL for my class is: http://webphysics.ph.msstate.edu/2213.html
I am still working on the content and would like to eventually include
some of your Java applets.
Obviously maintaining links to your Web site and proper credit.
I have noticed that you have your applets mirrored throughout the word
(which is nice)
and I am wondering if it acceptable for you to add another mirror in our
I am also interested in having a copy of the applets to run of laptop that
is not connected to the Web.
Actually, I am giving a talk about resources on the Web for teaching physics
to high school teachers
on the 20 th of February, and I hope to be able to include some of your
I will write a page with links to the applet in your site that I will use
in the presentation then place it on our server.
I appreciate your help. You are doing some neat stuff there.
Department of Physics and Astronomy
PO Box 5167
Mississippi State University
Mississippi State, Mississippi 39762-5167
Phone: (601)325 2923
Fax: (601)325 8898
Date: Wed, 11 Feb 1998 11:43:06 -0400
From: Hugo Beltrami <firstname.lastname@example.org>
To: email@example.com CC: firstname.lastname@example.org
Hello, I was looking at your site and I was wondering whether it would
to mirror it here at this university. Would you please let me know if this
Then I would contact our system manager Thank you for your attention
-- Hugo Beltrami
Department of Geology
Fax : 902-867-2457
St. Francis Xavier
P.O. Box 5000, Antigonish
Nova Scotia, Canada,B2G 2W5
Subject: Your Java Frictionnal Force applet.
Date: Mon, 9 Feb 1998 11:45:31 +0100
From: "leflocht" <email@example.com>
Thanks a lot for your on-line physics lesson.
As a french teacher i would like to ask you the permission to use your
applet on a new html sheet
using french as basic language. Of course i would only translate your words(
the best i can)
and leave each reference (native URL, mailto.. and comments in original
The reason is that i just gave my students, (aged 17) a exam using the
study of this system.
So i would like them to use your applet to get more of this study case
by using new parameters
such as Mu and various masses.
This page, if possible, will be added to the site i create for my sudents
(it's the very beginning),
you could surf at: http://www.chez.com/bup/index.htm and find it using
french "Fichiers de TP" in the 1S section.
---- You ask for suggestions ? Of course i've got some.
*first: The masses you use : Are F1 = 10 grams or F1 = 10*g where 10 is
kg and g is 9.81 mS-2 ?
(and so on for others )? case 10 grams: we use to calculate Force intensity
in Newton (France) case 10 kg:
the mass seems very heavy !
*second: Some lines of your HTML page are not readable for french users
because of the asian keyboard
translation,( i think.) Just above the definition table of forces, there
is a line i'dont know what it is ?
(caracters like @#& and others not in use in our alphabet but for bad
The definition for f12 is quite the same it appears like: f12j[number zero]m1
g[symbol for english pound] g
I think we must read: f12 not so different of m1. Mu.g. ad so on for each
reading of friction force. -----
I can make, if you look for it, other text translations, so your work to
make your work used by french people.
Thierry Le Floch Thanks to disregard my english mistakes.
Thierry Le Floch
Email: firstname.lastname@example.org site
Date: Sun, 01 Feb 1998 17:08:13 -0600
From: John Eagle <email@example.com>
I think this page is great.
I stumbled into it one night while trying to find some insight on a physics
assignment that I had.
I've used it ever since to check my work.
Something that might be helpful to a great number of people
would be a java applet with thick lenses and or two lense systems. Just
Thank you for taking the time to publish such a page John Eagle
*** Please check out Thick Lenses
Date: Sat, 31 Jan 1998 11:41:23 -0500
From: "Pierce C. Barnard" <firstname.lastname@example.org>
Hi, I was examining your satellite & projectile motion applet and I
found it to be very useful.
A suggestion, you may want to allow a user to set all paramters and
provide a button on the applet to start the applet.
This way the user will not have to keep on readjusting the applet while
the projectile is in motion.
Subject: Orbit applet
Date: Fri, 30 Jan 1998 08:44:52 +0530
From: "Surendranath Reddy.B." <email@example.com>
To: "Hwang" <firstname.lastname@example.org>
I just saw your orbit applet. It was just the thing that I thought I would
suggest to you.
Please consider the following suggestions.
Would it possible to show the initial position of the projectile,
its velocity and the angle the velocity makes with the line joining it
and the center of the earth
and then give the option to launch.
The distance from the center of the earth could be made large ( twice,
thrice.. the radius of the earth)
It would be better if the user gives these inputs by mouse clicks or by
entering the values.
( It may be also a good idea to relate these values with (gr)^0.5,
the value required for a circular orbit. One could bring out the concept
of escape velocity also.
Subject: Request for the secret!
Date: Tue, 27 Jan 1998 23:57:11 +0800
From: "Stephen, W. T. Kwan" <email@example.com>
I am Stephen W. T. Kwan, a secondary teacher in Hong Kong.
Your java applets are too amazing that I cannot help writing to you immediately.
Would you please mind telling me how you develop these kinds of programs
the time needed to do so?
Actually, I want to develop similiar programs myself in Hong Kong.
You can contact me through my e-mail address firstname.lastname@example.org.
Thank you for your attention.
Stephen, W. T. Kwan 27/01/98
Subject: Pulley and more...
Date: Mon, 26 Jan 1998 20:57:05 -0600
From: "Radim Kolarsky" <email@example.com>
Dear Dr. Hwang:
Thanks for fixing the link and making the page available again.
I have been looking for a while for this type of an on-line physics textbook.
Your page is just great.
Please keep up this good work. I work as a geologist/applied geophysicist
at Shell in New Orleans.
Originally, however I was born in Czechoslovakia and came to the U.S as
a political refugee in 1987.
I will never forget my high school physics professor (whose picture my
wife and I keep on our web page)
I had there as a student. He did quite a bit for me.
Thanks again. SHould you efer come to New Orleans (a convention perhaps)
please do not hesitate to let us know.
Subject: Pulley Experiment
Date: Sun, 25 Jan 1998 13:14:53 -0600
From: "Radim Kolarsky" <firstname.lastname@example.org>
Dear Dr. Hwang:
My son and I have enjoyed visiting your site today and yesterday, looking
at your experiments.
In an effort to assembe information for my son's school science project,
we attempted to see the "Pulley" page but, unfortunately, the link is broken.
I have marked your site among my bookmarks and will definitely come visit
Radim A. Kolarsky
Subject: This site is so cool!!!
Date: Fri, 23 Jan 1998 16:10:28 -0600
From: Michele Gale-Sinex <email@example.com>
Thanks for sharing it.
center for integrated ag systems
Subject: Doppler effect and shock wave
Date: Sat, 17 Jan 1998 20:49:55 +0700
From: Amrat Chawla <firstname.lastname@example.org>
Even though I am in trading business, in my personal time I am very much
interested in Physics
and I bought some 1st year university text book to study Physics as hobby.
But frankly, your web site give me a very clear lesson just in few days
that I discovered your site I understand a lot !!.
For example I try to understand the sonic-boom but even I read many time
I still cant get it,
but with just few minute of virtual experiment with 'Doppler effect and
shock wave' it became clear to me !!
Really thankyou very much for your site.
I regard you as my teacher.
With respect and best rgds.
Subject: RC circuit applet
Date: Sun, 11 Jan 1998 06:41:16 +0000 (!!!First Boot!!!)
From: "Samara, Thomas Nick" <email@example.com>
Thanks alot for your program.
I couldn't quite find in the book a description of what the current was
doing while the capacitor was charging.
Please make more programs like it.
Subject: Superposition of waves
Date: Mon, 15 Dec 1997 20:37:48 +0100
From: Peter Ryder <firstname.lastname@example.org>
Organization: University of Bremen
Your Java applet for superimposing wave is very nice,
but the "medium" has the interesting property that the group velocity and
the phase velocity have opposite signs!
Well, that makes an intersting problem for the students to discuss.
Subject: standing wave
Date: Wed, 03 Dec 1997 10:26:03 +0000
From: Keli Sato <email@example.com>
Organization: Addison Wesley
Hello, I visited your Superposition Principle of Waves (http://www.phy.ntnu.edu.tw/java/waveSuperposition/waveSuperposition.html).
The applet is great, but I think you ment to say Standing wave, not Standarding
Date: Sun, 26 Oct 1997 08:49:37 -0800
From: Ursula Sexton <firstname.lastname@example.org>
Hello, Mr. Hwang, I am an elementary science teacher,
as well as a leader in science education reform in the state of California.
I train teachers and while searching for some physics principles, I found
the Web site with your applets.
I was interested in seeing your rainbow demonstration. It is so wonderful!
This site is just full of great demonstrations for clarifying principles
that teachers just can't seem to grasp,
unless a visualization tool is provided. This is just great!
I thought I'd mention that there is a small mispelling at the bottom of
your rainbow page.
Your last bullet reads: "Did yo noticed that rainbow consists of partially
It should say - for grammar and spelling to be correct:
Did you notice that the rainbow consists of partially polarized light?
Best of luck in your journey to share with others the wonders of science.
Thanks for the gift of your knowledge and the wonderful medium to share
Subject: your educational Java applet(s)
Date: Mon, 20 Oct 97 17:53:34 -0700
From: Martin Koning Bastiaan <email@example.com>
To: "Fu-Kwun Hwang" <firstname.lastname@example.org>
Dear Java Educational Applet Author,
Thanks for creating a great educational applet and making it available
on the WWW.
Your Java applet is pointed to by the Educational Object Economy (EOE),
located at http://trp.research.apple.com/.
Apple Computer, Inc.零 EOE Team is preparing to distribute an EOE framework
(which we雹e calling the GOE--Generic Object Economy)
and its URL directory to groups who wish to set up their own EOE.
Please reply to this message if you would NOT like a pointer to your applet(s)
(shown below) included in this release.
If you have written other educational applets in Java and would like to
see them included in our EOE database,
please contact us. You can even enter your applets into our database yourself,
If you find any out-of-date or incorrect information, either listed below
or on our site
(which contains more thorough descriptions of the Java applets than is
please let us know so that we may update our records.
For more information about the GOE: http://trp.research.apple.com/info/goe.html
Martin Koning Bastiaan,
Educational Object Economy
Date: Fri, 17 Oct 1997 13:19:20 +0000
From: David Johnson <email@example.com>
Organization: Douglas High School Science Department
I've used your vector addition and vernier caliper applets in my physics
and physical sciences classes.
I'm just sending this note to thank you and ask you to keep up the
Date: Tue, 7 Oct 1997 00:29:04 +2.00
From: "H L Botha" <firstname.lastname@example.org>
Organization: Iscor Profile Products
Hallo Mr Hwang
I enjoyed your web site , good work !!
Herman Botha (South Africa)
Subject: pulley applet
Date: Fri, 26 Sep 1997 09:21:00 -0400
From: "Robert B. Muir" <email@example.com>
Organization: Physics & Astronomy, UNC Greensboro
To: firstname.lastname@example.org, email@example.com
You have done a very good job developing these wonderful applets.
I have not run all of them yet, but look forward to doing so.
I just tried the Pulley applet and had a problem.
It seemed to download, but nothing ever appeared in the display area.
The text below the display area looked ok.
I am running Netscape Communicator 4.01 on a 166 MHz Pentium with 30 Mb
All the other applets I have tried worked ok.
Thank you for making this material available to us all.
Sincerely yours, Bob Muir
Physics & Astronomy
U North Carolina at Greensboro
Greensboro, NC USA
Subject: java and sound
Date: Fri, 12 Sep 1997 14:19:41 +0800
From: "Harlan W. Lefevre" <firstname.lastname@example.org>
Dear Dr. Hwang,
I have used several of your applets in my physics courses here.
And I asked our people to mirror your site here for fast access.
The applets are really useful. Thank you.
I usually roll an NCD Xterminal into my classroom and use a remote Sun
Unfortunately java only writes audio to /dev/audio and Xwindows won't deliver
the audio to the Xterm.
So the beauty of your Fourier Synthesis program is largely lost when one
can't do the sound.
Do you have a solution to this problem?
Date: Sat, 06 Sep 1997 14:18:50 +0800
From: Cho-Teng Liu <email@example.com>
Dear Prof. Huang:
Your web pages are very exciting and it deserves an award in education
A minor suggestion:
While watching some of the experiment, e.g. the RC充/放電 電路,
the browsers will be more comfortable if they can view both the figure
and the text on the screen.
Therefore, I would like to suggest that
1) add a scroll bar for the text, or
2) place the title and figure on the left frame, and the text on the right
Congratulation to your accomplichment.
Subject: Your Physics Web site
Date: Wed, 03 Sep 1997 16:20:01 -0500
From: Narsing Rao <firstname.lastname@example.org>
Organization: Bethune-Cookman college
Hello Dr. Wang:
I just browsed your physics web site. I am really impressed by what
I am sure my students will find it very useful and exciting.
I am not a programmer either, and just now I am trying to learn about HTML
and JAVA etc.
So long. I 'll be watching more of your pages.
Subject: EM wave Applet
Date: Mon, 01 Sep 1997 17:34:13 -0700
From: "Sunil K. David" <email@example.com>
Organization: Bethune-Cookman College
To: firstname.lastname@example.org, email@example.com
Hi: You have made my job quite simple in showing the prop. of EM wave for
Congratulations. Great applet. Goodluck, Bye,
Sunil K. David, M.Sc., M.Sc. Ph.D.
Assistant Professor of Physics
Subject: WOW! Great sight
Date: Fri, 29 Aug 1997 16:48:04 -0600
From: Gary S Smith <firstname.lastname@example.org>
John P. Cise..Fac. Austin Com. College
Date: Wed, 20 Aug 1997 16:29:26 -0500
From: "efra璯 barbosa" <email@example.com>
Dear Prof. Hwuang:
I am also a physicist. I live in Bogota, Colombia.
I enjoy your simulations very much. It was a great work done by you. Congratulations!
Subject: Buoyance force
Date: Sat, 16 Aug 1997 07:09:52 -0500
From: "K. M. Isaac" <firstname.lastname@example.org>
Organization: MM Enterprise
Your buyancy force animation is very good. I plan to use it in my fluid
K. M. Isaac University of Missouri-Rolla
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