This is just to say thanks for your java applet. I bought a vernier
recently
and couldn't work out how to use, but then I found your applet
and it all
became clear.
David
I am now studying the Relative Motion applet, it is most interesting to see clearly the things we notice in everyday life.I have had some holidays boating on rivers and I can picture the effects clearly as I use the applet.While driving a boat it's speed relative to the current is most apparent, particulaly when trying to moor.
Thanks again for such an interesting web site
Best Wishes Ray Holloway ray@middx.screaming.net
Hi
I have only just found your wonderful web-site & have tried the
accident
experiment, it really is
a good lesson for us drivers.Perhaps it should be
included in driving tests.
I had not appreciated the "knock on" effect until I noticed that although
I could stop in time those behind me could not.
I found that at 100 mph I had to allow 75 feet between cars for them
all
to stop & even then it was not succesful every time. A wet
road would of
made it much worse.
Thanks for a very interesting site, although I have no formal education
in
Physics I find it fascinating, so I am going to try the other experiments
now.
Regards, Ray Holloway
ray@middx.screaming.net
Hi
I was recently scouring the net looking for a suitable picture to
demonstrate the orthogonal mode of an electromagnetic wave in an optical
fibre for a presentation on polarisation dispersion (my artistic skills
are
nil). I came across your moving Java applet description of an EM
wave and
was suitably impressed as its exactly the type of picture I'm looking
for. I
was wondering whether you might have still pictures of the sort that
I might
be able to post in a Powerpoint presentation. If you do I would be
much
obliged. Thanks
Regards
Arif Zubairi
Product Engineering
Nortel Networks
External: % 0181 945 3720
ESN: % 730 3720
E-mail: ) zubairi@nortelnetworks.com
thanks kindly. Much appreciated.
This is cool dud!!
Good day,
I checked your E/M applet today. Maybe you can help me out...
When I set both E and M fields to zero, I would expect the particule
to
move at a constant speed in a constant direction (or possibly stay
still).
Yet, no matter what I do, it doesn't seem to work.
I am just trying to show to a friend that a charged particule standing
still in a magnetic field won't feel a thing... if there is not E field.
Your applet would be perfect... but it doesn't give the desired result.
Daniel Lemire
Subject: Re: applet
Date: Fri, 15 Oct 1999 22:11:30 -0400
From: Daniel Lemire <Daniel.Lemire@Videotron.ca>
To: Fu-Kwun Hwang <hwang@phy03.phy.ntnu.edu.tw>Thanks for your quick reply!
Dear Fu-Kwun Hwang
Your sight is very very interesing and very very
helpful for us. If you like physics problems we can
send you what we have. We think that our relationship
can be very helpful for you and for us.
Sincerely yours, physics club of lyceum "Leader" Kiev
Ukraine(post Soviet republic)
nice page.
thank you.
Cool Stuff!
I have just recently discovered your web site in an article in "The
Herald"
newspaper which is published in Glasgow, Scotland. I have visited
your site
and was very impressed with the work that you have done. I intend to
get my
Physics students, who study at Kilwinning Academy, Scotland, to access
your
site as part of their coursework.
thank you
Charles Scott
Dear Mr. Hwang,
Referring to the kepler motion applet in the below
add.
http://www.phy.ntnu.edu.tw/java/Kepler/Kepler.html
I find it very interesting. However, I have some
difficulties when using the applet.
1. For second kepler law, the area of the shaded area
and non-shaded area should be the same. However, there
is no data showing what the area is.
2. for third kepler law, i observed that there is no
indication of the period of the planet. There is this
T value indicated in the applet but it is not the
period. i would appreciate if you can explain what the
T value is.
thank you.
best regards
leetaishen
Back in school after a tough summer. My 81 year old mother was visiting
from USA and fell down a stairs and needed help for the 2 months she
was
here. Bad luck! Didn't get much done this summer. But the weather was
nice at least.
Hope you扉e had a good summer.
I was checking to see if you multimeter
aplet could be used to see in
what situations it would be incorrect (parallell with a LARGE
resistance) but it didn't take that into consideration- it gave the
same
reading at 2000 kohm as 10ohm.
See the accompanying picture.
While I惴 at it heres the interpreter for Q basic
in case you want to try the files I sent before.
I've been looking at Walter Fendts Javas. some are quite illustrative.
One that wasn't was about the "radioactive decay series". Do you have
anything planned there?
I'd like to find an alternating current aplet that would show the charge
acculation resp magnetic field buildup graphically.
I sometime try to show my pupils a water -electricity anology where
pressure=voltage
liter/sek=A
pump=voltage spource
small or clogged pipe=resistance
double chamber with elastic membrane=capacitor
turbine with inertial load=inductance
That might be something that could make an interesting Java aplet
I put together a very rough sketch of the C-L anology:
Jeff Forssell
personal homepage: http://www.torget.se/users/i/iluhya/index.htm
my village technology homepage: http://home.bip.net/jeff.forssell
Swedish National Institute for Distance Education (SSVH)
Box 3024 SE-871 03 H酺n飉and /Sweden
tel +46(0)611-55 79 48 fax +46(0)611-55 79 80
schools homepage www.ssvh.se
Subject: SV: re send multimeter plus more ideas
Date: Thu, 16 Sep 1999 12:40:29 +0100
From: Jeff Forssell <JF@ssvh.se>
To: "'hwang@phy03.phy.ntnu.edu.tw'" <hwang@phy03.phy.ntnu.edu.tw>Thank you!
The aplet seems to work very well.
Some minor problem and a couple of wishes:
1) if I change the range while the meter is connected, the measured
voltage is not updated. (Hmm I tried it again and now it works. But if I
reload the page and turn "ON" directly it reads 4,67V on 10 V range. If
I change to 50 V range,4,76V stays in stead of 4,95V The Equivalent
circuit is updated directly.)
2) I would prefer a much faster component value change while
continuously pressing mouse <0.1s per change. One can always "fine tune"
with single klicks.
3) I would like a possibility of writing in R2 values also.
(4) Fu Hwang 1999 in lower left, in stead of 1998)
Subject: SV: SV: re send multimeter plus more ideas
Date: Fri, 17 Sep 1999 07:46:05 +0100
From: Jeff Forssell <JF@ssvh.se>
To: "'hwang@phy03.phy.ntnu.edu.tw'" <hwang@phy03.phy.ntnu.edu.tw>
CC: Claes Ahlin <AI@ssvh.se>Thank you!
I still have the problem with voltage update on changing range even on
the new aplet (i've tried in both NS 4.5 and IE 3.0).with a newly opened page:
press ON
V= 4,76V 10 range
change to 50 V V still 4,76 (equivalent circuit Rs update
properly)
change to 10 V v changes to 4,95
change to 50 V changes to 4,76The write in window for the values works well. I would (on behalf of
Sweden and some other countries) like even comma "," to be interpreted
as a decimal sign.Other clarity wishes: prefix the box with "R2" when updating R2 and
suffix the box with "kohm" when R values being set.V [ ]
R [ ]kohm
R2[ ]kohmI think the current circuit would be easier to see if you had a wire
connecting rather than 2 ground symbols.When the Rm box is not checked, it would be good for the Eqivalent
circuit to be altered perhaps like this:Hope you don't think I'm complaining! I use your aplets a lot! I wish
someone would go through my stuff to help me develop it!
Subject: Very Nice ..... but....more ideas
Date: Sat, 18 Sep 1999 22:12:40 +0100
From: Jeff Forssell <JF@ssvh.se>
To: "'hwang@phy03.phy.ntnu.edu.tw'" <hwang@phy03.phy.ntnu.edu.tw>Very nice!
But I still get the update problem when changing range (both IE 3.0 &
Nets 4.5). Have you tried as the FIRST step after opening the page? I
know that the problem goes away if I do a bunch of other stuff (change
values I think).One other problem: I think that the multimeters that I扉e used have had
the red lead positive when in the resistance mode (which makes it
easier to interpret when measuring on active components like diodes). I
havesn't checked that in reality since I had the thought though.Reviewing my own work:
I'm mainly interested in getting my web resources polished up for my
Swedish students which mean that it is in Swedish which makes it
difficult for non Swedes to say much about it.
I have been visiting your site this morning (found via AltaVista) and
playing with the java applets.
A great resource and very educational. Thank you!
Seth Bell.
hi there!
really nice java applet, though it
took me some time to figure out
why it said wrong answer all of the time when i was completely sure
i
got the right one. i had to type 1.0 mm instead of just 1mm, and that
was quite annoying. if you wanted a tip, i guess that is one. keep
up
the good work!
Jonatan
Dear Dr. Hwang,
I have used some of your
physics applets and I find them to be excellent.
Well done! At the moment in the Physics Department we are making changes
to
our first year physics labs and would like to include your Vernier
applet
in one of the labs in order to help the students learn to read a vernier
scale properly. Is is OK if we include the applet in one experiment?
Thanking you in advance,
Yours Sincerely,
Dr. Cathal Flynn
Department of Experimental Physics
National University of Ireland
Galway
Ireland
Dear Sir,
Your mixing light beam applet is very very instructive. When I show
to
my children they were amazed and understand easily of what they learned
at school but never get it clear. You know how schooling in Thailand,
education here is mostly memorising and answer question ! So we parent
have to help our children understand by external help. Your applest
is
very helpful tool.
Thankyou for your contribution to people of the world.
With best rgds.
Amrat Chawla.
WOW!!!!!! Reflection and Refraction is WONDERFUL!!!!THANK YOU
Leslie Marra
lmarra@excite.com
you can send at my address today. Is urgent!
Very interesting and educational java applet, sir. My compliments.
I am not an astronomer but studied Kepler's
laws years ago. Your applet
is the best tool I have ever seen to allow one to grasp the concepts.
Thank you for creating and sharing it.
Cheers,
Greg Hecht, MCSE
The Riverpoint Group, Ltd.
Kansas City
Dear Sir,
I appreciate the Physics animations from you very
much ! I want to learn java so that
I can make my animations. Would you please give me some guides
by introducing
some reference books and related materials ? Thank you very much
indeed !!
P.S. I am a Physics teacher. I have certain programming
knowledge of Basic and
Pascal.
StyleWan.
Nice java applet..
Demonstrates very nicely what I was experimenting on with golf balls
Your entire site is wonderful! Thanks for taking the time to make
this
excellent information acccessable to my students!
Edie Dukek
Dear Fu-Kwun,
I appreciate your web pages: Billards
and Physics, and 2D Collision.
I am a high school science teacher, preparing to teach an "Integrated
Chemistry and Physics" class, and I anticipate using your web pages
in the
classroom. Thanks!
Carrie Doyle
Thank you very much for this web site; extremely interesting.
I work with
physics, chemistry and computer programming, and find this very helpful.
Monty McGee
Florida
U.S.A.
I am in a bit of a hurry with other things also, but I have looked at
the
applets and they look good!
You made a very nice interface for seeing the reflection of different
polarized waves. Both numerical and visual without cluttering up the
previous features!
Jeff Forssell
personal homepage: http://www.torget.se/users/i/iluhya/index.htm
my village technology homepage: http://home.bip.net/jeff.forssell
Swedish National Institute for Distance Education (SSVH)
Box 3024 SE-871 03 H酺n飉and /Sweden
tel +46(0)611-55 79 48 fax +46(0)611-55 79 80
schools homepage www.ssvh.se
residence +46(0)611-22144
>----------
>Fr幩: Fu-Kwun Hwang[SMTP:hwang@phy03.phy.ntnu.edu.tw]
>Skickat: den 7 juni 1999
03:20
>Till: Jeff Forssell
>Ang嶒nde: Re: SV: SV: Doppler applet
wish (& propagation)
>
><<Fil: Doppler.html>><<Fil: Doppler.class>><<Fil:
propagation.html>><<Fil:
>propagation.class>>
>Jeff Forssell wrote:
>
>> I notice that if I enter a user ratio in propagation, the top and
bottom
>> field maintain the colors it had before, no matter whether the ratio
is
>> more or less that 1. Maybe it would be good to have the optically
more
>> dense media become gray.
>>
>> I see that you have put in the angles also. I thought
of suggesting
>> that but I forgot to write it.
>>
>> A new idea I got was is: could the intensity of the beam colors
show how
>> much of the radiation is reflected and transmitted. No big
need, but it
>> would be nice, even if just approximate. But that would be complicated
>> because polarization comes in also. That would be a challenge! Maybe
>> better with a separate applet. But you have made some amazingly
compact
>> versatile applets before. (Like the lens /mirror one!)
>>
>
>Try the attached java applet and let me know if this is what you want.
>Pick p-wave or s-wave from the top left selection.
>
>
>>
>> I think there maybe is a serious flaw in the doppler
applet: example
>> with the default settings the wavelength is supposed to be 20. If
I
>> measure on the right it is 20 and left it is 60 if i
change the speed
>> to 4 the measured distance between wavecrests becomes: 42 38
which
>> seems to indicte that the wavelength is actually 40. I' m
in a bit of a
>> hurry until wednesday so I may have made a mistake.
>
>In my previous java applet, the distance between wave front is not
necessary
>related to the wavelength. Those are wave front generate at fix time
interval
> not necessary equal to period of the wave).
>In this attached java applet it is modified so that the wave front
is
>generated
>with the same period of the wave. Try it and let me know what you
think.
>
>I will try to add sound effect at the next release.
>But you will have to wait a few days,
>I will have to do other stuff first.
>
>
When I wrote a moment ago about a BASIC program I had and decimal
acceptance, I got to thinking maybe your applet could be expanded (or
a
new one with similar components so It could replace this program for
practicing reading analog scale instruments:
It is written i Qbasic. (There is also less common scale where range
12
V is to be interpretted from a printed scale with 6 V as full scale-
I've seen similar things in reality but that aren't very common so
I
might take that away.)
That I don't have more scale divisions depends on 2 things:
1) I want students to practice estimating tenths of scale divisions
2) lack of time (laziness?)
I m sending this qbasic file (and another on Vernier scale)
As a friend of "old" computers I have versions for CGA and Hercules
screens too
Jeff Forssell
We do end our sentences with . though.
I was amazed to hear from you so quickly. I found myself wondering what
is the time In Taiwan? We are at 17 degrees longitude and taiwan at
120
so that should mean that when you sent your letter it must have been
around 6 pm your time. (I don't know if you use Daylight saving time
there).
Both the class files were smaller than the old ones! How is that
possible? Did you do some code cleaning when you added features?
Were you able to open the Qbasic files?
Dear Mr. Hwang
I visited your WEB page with hte aplicattions on JAVA to demonstrate
some Physics
laws and I found it very interesting.
I would like to send you my congratulations for your work.
Perhaps my Physics students may use and learn more science with your
simulations.
Sincerely, Tarso.
Physics Departament of Universidade Federal de Santa Catarina.
Hello I`ve visited your homepage, and I must say that I found very
wonderful and despite I did not see you or talk with you, I liked you,
thanks for your hardworking. I appreciate you, if you accept.
Good luck.
Ege University
Department of Computer Engineering
senior
Derya Oktay
deryaoktay@hotmail.com
icq# 23349443
Thank you so much for the creative and very effective physics applets.
I am
a high school physics teacher and I use them frequently on my physics
pages.
L Woolard
<A HREF="http://members.xoom.com/lizwoolard/Enloe_Page">Enloe
Physics Web
Page
</A>
Are your Physics Java applets for sale. I find them very interesting,
but due the cost of Internet phone calls (ie; in the U.K.) I'd rather
install them on my PC.
Thank you
Rhys
I like the doppler applet (as I do
most of your Javas) but when I was
about to try to use the x,y coordinate display to measure the difference
in apparent wavelength on different sides of the source, I found that
the display changed to angle. Which is very good in some cases but
it
ought to be easy to have both. Either i 2 windows or perhaps left click=
angle, right click=coordinates
Another wish would be that the "propagation
applet (which I love!) could
have the top medium become darker than the bottom when it愀 n value
is
greater and increase the choice of n1/n2 to include day glass about
air
below. (I know and appreciate the possiblity to set the n/n ratio to
0.667, but if you feel like adding something I悲 appreciate the above)
thank you
Jeff Forssell
personal homepage: http://www.torget.se/users/i/iluhya/index.htm
my village technology homepage: http://home.bip.net/jeff.forssell
Swedish National Institute for Distance Education (SSVH)
Box 3024 SE-871 03 H酺n飉and /Sweden
tel +46(0)611-55 79 48 fax +46(0)611-55 79 80
schools homepage www.ssvh.se
residence +46(0)611-22144
Subject: SV: Doppler applet wish (& propagation)
Thank you! That was fast!
The doppler applet is more flexibla now. I would though prefer if one
could lefdt press and drag between 2 freely chosable points and get
delta x, delta y; rather than only distance from source.
Another detail is that the y coordinate is negative upwards which
is
not the most common matematically, though those distances aren't so
interesting.
You might be interested to know that the doppler applet was referred
to
in one of the questions in the latest National Exam in Physics. But
we
aren't allowed to disclose the contents. (So erase this letter :-)
)
I assume the index.html page was in Chinese (It sure wasn't English!)
The propagation applet is perfect. Whoops I just noticed that
for large
angles of incidence, the incident beam became solid red!
Subject: SV: SV: Doppler applet wish (&propagation)
Date: Mon, 31 May 1999 05:43:14 +0100
From: Jeff Forssell <JF@ssvh.se>
To: "'Fu-Kwun Hwang'" <hwang@phy03.phy.ntnu.edu.tw>I notice that if I enter a user ratio in propagation, the top and bottom
field maintain the colors it had before, no matter whether the ratio is
more or less that 1. Maybe it would be good to have the optically more
dense media become gray.I see that you have put in the angles also. I thought of suggesting
that but I forgot to write it.A new idea I got was is: could the intensity of the beam colors show how
much of the radiation is reflected and transmitted. No big need, but it
would be nice, even if just approximate. But that would be complicated
because polarization comes in also. That would be a challenge! Maybe
better with a separate applet. But you have made some amazingly compact
versatile applets before. (Like the lens /mirror one!)I think there maybe is a serious flaw in the doppler applet: example
with the default settings the wavelength is supposed to be 20. If I
measure on the right it is 20 and left it is 60 if i change the speed
to 4 the measured distance between wavecrests becomes: 42 38 which
seems to indicte that the wavelength is actually 40. I' m in a bit of a
hurry until wednesday so I may have made a mistake.
Subject: more ideas for doppler and propagation applets
Date: Wed, 2 Jun 1999 09:29:17 +0100
From: Jeff Forssell <JF@ssvh.se>
To: "'Hwang'" <hwang@phy03.phy.ntnu.edu.tw>
CC: Claes Ahlin <AI@ssvh.se>I just got an idea f顤 the doppler applet that I hope you will like:
[ ] listener in top partif someone checks in the box, the user can place a "listner" anywhere in
the window.
Whenever a wavefront passes him the computer makes a sound (a beep or
tick or something).
For example: I place my listner in front of the advancing source:
beep beep beep beep beep (then it passes) beep beep beep beep
If I place my listener off to the side I would get a less pronounced
effect
(what should happen when a supersonic "bang" arrives should of course be
some loud noise).Another wish for the propagation applet:
increase the n1/n2 options with "diamond to air". I think people
tend to be fascinated by diamonds and they do have a spectacularly
high n value. (I saw that in another persons refraction applet, which
also included the possibility to show wavelength changes (also different
colors for the different wavelengths) but I prefer yours otherwise)
Thank you for your answer. I have a lots of tests to grade now at the
end of the term. Perhaps it is the same for you.
Hallo Mister Fu-Kwun Hwang,
thank you very much for sending all the files. To get a
good multimedia lesson is very important for me,
because it would be evaluated. A good evaluation will
give me a job es teacher.
I tried to understand your program. It's not easy
because my knowledge in Java is very basic. My problem
is now:
If I want to change the power of r in aceleration or
force F~ a ~ 1/r^2 to
F~ a ~ 1/r^x
then I have it to change in the method drivs of class
movingProjectile. (it works)
But this method never is called in whole
projectileOrbit.class. And to give a different exponent
to acceleration I have to give a argument to method
derivs (or are there other possibilities.
Is it possible that derivs is callt in rk4.
Could you send me please rk4.java or could you help me
in an other way with an idea to cahnge it.
Sorry that I ask you so much. Probably your time is
rare, but it would be a big help for me.
Thank you very much
Peter Brichzin
P.S: To get an imagination whatb I want I send you a
modified version: I added a Checkbox to change force.
But I can't get the connection between checkbos and
method derivs.
Fu-Kwun Hwang,
Hello, I am an amateur American physics enthusiasts.
Your physics
page has caught my attention and I would like to let you know they
are wonderful.
Under Dynamics on 6. Circulation
motion and Centripetal force, I
would like to know if it possible to change the velocity of the circular
motion and change both the weights on either end of the string without
changing it's radius?
Thank you,
Michael Blackstock
Subject: Re: Physics applets comments
Fu-Kwun Hwang,
Thank you very much for the adjustments you made
to the following
request I sent you!
Sincerely,
Michael Blackstock
I have found the tansverse and longitudinal waves. They are excellent,
exactly what is needed. Being able to show the the phases of particles
relative to each other is very useful.
I will be able to direct my students to your site so they can see for
themselves.
Once again thank you for your efforts the results are most pleasing.
Mr.A.E.Vinters.
Rishworth School
Dear Fu Kwun Hwang,
I have received your applet. This is fine, the diagrams look exactly
right. I cannot run the applet as my email seemed not to contain any
software to animate the diagrams, only the pictures themselves. Can
you put this on your site so I can try it out?
Perhaps you would consider writing an applet to show a how a
Transverse wave is made up of oscillating particles: this would
be a
most valuable teaching tool.Also a Longitudinal
wave to show how the
wave particles vibrate in the same plane as the plane of propagation?
Both applets would work well alongside your excellent SHM applet.
Once again thank you for answering my request, certainly material
such as this makes Physics much more enjoyable to teach and learn.
With very best wishes,
Anthony Vinters. Head of Science Rishworth School.
Dear Fu Kwun Hwang
Thank you for the Applets, they are excellent! I have used them for
teaching
my students about Simple Hamonic Motion
and the Principle of
Superposition.
Have you done one which shows the motions of particles within a Transverse
Wave and a Longitudinal wave?
It would be interesting to look at the
particle motion and compare them within these two wave systems. If
it were
possible to show the phase relationship between any of the particles
even
better! Showing that any particles that are 2Pi radians out of phase
with
each other are 1 wavelength apart is something that students can find
difficult to understand without the help of a moving model.
Once again thank you for all your work.
With best wishes:
Mr.A.E.Vinters.
Rishworth School
Dear colleque
Your site is vere good, but it is very difficult to load. It takes more
than 30
minutes.
Yours sincely
assistant professor Soeren Roejel
The Technical University of Denmark
Copenhagen
email: sr@akp.dtu.dk
An applet that would be invaluable in teaching how light and color work
would be one that had a flashlight with different color filters red,
green,
blue, cyan, magenta, yellow, clear. Then the user could view
various
objects in those same colors using the flashlight. This would
be an
illustration of how "classical" color reflection works.
I am a physics teacher from Parma, Italy, and I had much appreciate
your
applet, that I 'll use during my school lesson. Excuse my poor english,
but however congratulations and thanks for your good work!
Paola Pannuti
dear mr. hwang
thank you for helping! now it works!
sincerely, stefan berger
hi..
thanks 4 the help
my teacher liked the animation...!!!
and the rest of the class too..!!
once again thanks
http://www.upb.edu
dear mr. hwang,
i'm a teacher for physics in germany. this is the third time i launched
your site in the internet. but when i try out your applet i get problems
by changing the number of particles. always i'm trying to change this
value it doesn't change the number of particles in the applet. can
you
help me?
sincerely, stefan berger, bochum, germany
Great Demo, I'll use it with my students.
Thanks
Stan Treanor
Dear Sir,
I am a Physics teacher in a secondary school in Hong
Kong. I found that the java
applets in your web page are excellent teaching materials !!
It would be great to save
the applets for teaching. However, I could not save the java
applets (together with the
homepage) so that I can play them offline. Would U please help
me ?
Thank U very much indeed !!
StyleWan.
Your application in java to learn how to read a vernier help me.
Dany Marquis
RDS
Montr嶧l
I would like to commend you on a wonderful site. The Vernier site
is informative and
fun. I wanted to get your permission to link to your Vernier from a
Cumberland County
Educational Physics course website. It was suggested to us that
we get permission to
link to any sites so that we don't infringe on any copyright laws.
I appreciate your hard
work.. You can respond to cmclean@webacademy.net
Thank -You for your time.
Carol McLean
Teacher
Mr Hwang:
First of all, i would like to congratulate you about your PHYSICS HOMEPAGE.
I'm an 18 year old student from Mexico. I study Mechanical and Electrical
Engineering at the ITESM here in my country.
Now your are probably asking: so, what?
Well, i'm taking a physics class in which we have to make several different
kinds of thing on computers...one of them, make a HOMEPAGE and include
some
links to virtual labs ans stuff like that.
I managed to link some of your applets to my page, that the whole meaning
of
this e-mail, to ask for your permission to keep those links, or if
you
disagree, just send me an e-mail, and i would gladly erase them.
You can check my homepage (that it hasn't been finished yet) at
http://members.xoom.com/fisica_dos/index.html
and tell me your thoughts.
I would apreciate you could let me keep the links.
Thanx
Saludos desde Mexico.
Hi Professor,
I visited the your E&M
website and I am very impressed with the animation
of the E&M waves. I especially liked the rotations of axis.
Good Job
-Peter
I happened upon your web site and noticed that the word "Beginning"
is
misspelled (you have it as "Begining"). The URL of the page is:
http://www.phy.ntnu.edu.tw/java/comments.html
I hope this helps.
Chris
Thank you! I know almost nothing about physics, but I have had a
great time playing with the applets on your website. I was actually
looking for some simple information for a 13 year old about how
gravity keeps the planets in our Solar System in their orbits, but
I
soon forgot about that in the sheer fun of playing. Thanks again
Bob Arkley
Hi
I was looking at your applet for the thin lens and really liked it.
I am new to applets and
often it is possible to download them so that you can use them off
line but I couldn't
work out what to do to download your applet.
I am a secondary teacher and would really like to show it to my students.
Would I be
able to get a copy of it please.
Thanks
Pam Evans
pev@netspace.net.au
pevans@mentone.gsat.edu.au
I liked your sight. And found it very informative. Hands
on experience works
better than just reading the info. Thank you.
Your site is fantastic!
I teach high school physics and have been looking for good simulations
to use with my students! This one is a winner!
Very talented work! Keep it up and thanks!!!
Lars Wendt, Hunterdon Central Regional High School, Flemington, NJ .
U.S.A.
Your caliper java applet is cool -
Brad Busch
VP Engineering, Class1 Inc.
hey, you're really good. i like your webpages alot. our physics teacher
referred us to your pages, and i think they're pretty cool, especially
with the animations and interactive applets. and plus my mom's heard
of
your university (i'm chinese), so rock on!
I don't have any suggestions, but I think your site is really great
and
I like your graphics.
Susan Irlbeck -- physics student in Raleigh, North Carolina, USA
your webpage is awesome! my physics teacher, Ms. Woolard,
(lizwoolard@hotmail.com) assigned us your webpage as our homework tonite.
you
have done a great job! thanks!
stephanie yeh
bananas337@aol.com
WOW! my physics teacher (Mrs. Woolard) suggested your website
as an extremely
useful tool to help us learn about oscillations and SHM, as well as
other
physics concepts. your site really is truly wonderful and it is obvious
that
you have put plenty of time into making it. it has been very
helpful in
clarifying some places where i was having difficulties. i am
so glad my
physics teacher gave me your website address and i would
like to congratulate you on such a wonderful job.
shefali oza (north carolina)
Hello, I am a physics student living in the US. My teacher gave our
class
your web page address to help us learn about waves and oscillations.
I thank
you for you taking the time to write the java for these demonstrations.
They
helped me learn the material.
Thank you,
Brian Senter
Sir,
Your applets are verry-2
good but your server is very slow
,forcing not to even approach your site.
thank you
From the Fermat page: "I am not a professional programmer, I am a physicist."
....but you're pretty good at both. :)
Great stuff. Thank you for your work.
Dear Mr Hwang,
Hi there. I'm teaching physics in a secondary school
in Singapore. I've
found your applets very useful in my teaching but wonder if it is possible
for them to be downloaded into my computer so that I do not need to
access
the internet everytime I wish to use them in my lessons. Would appreciate
it
very much if you could make the applets available. Thanks.
Mr Tay Kian Hwee
Hi Mr Hwang:
I?m from Brazil I worked as Physics about 10 years ago and since
that time I had a desire : to make softwares for Physics teaching.
The DOS interfaces I used to have forced me to give up. Last year
(after spendig some time learning Windows based programming) I
restarted the project but once again I didn?t like the results.
I
used Delphi 3.0 (Pascal Object Language) and made about 100 programs
( mechanics and eletricity) but when I saw your programs I felt even
more disappointed with the ones i had done . Yours are brilliant ,
fantastic . Don?t you sell them ? I?m interested in many of them.
One : sugestion: Don?t use weak green colors I hardly can see them
.
For instance the one you used in Vactor addition,
Thank you and congratulations for your excellent work (I wish I was
talented as you are)
Marcilio Carneiro
Dear Sir:FU-Kwun Hwang.
I am a High School teacher from La Corunha , Spain ( Galicia ) near
Portugal.
I realy like yours appelets of Java and I am used to work
with them in
my classes.
If you don`t mind I would like to know if is posible for you to do
one
about this:
A force pulling a block on a slope, and showing the forces growing
when
you aplay diferents pulls.
Also it would be a plesure if you could do another one: a block
moving
in horizontal , changing the force angles when you pull the block,
and
at the same time showing the celerity of the block. The most eficient
angle to move is when the tg (angle) = coefficient of rubbing
Sorry for my english
I?m very pleased for having found your work, amazed work, which is very
useful for my students and also for me.
Before all, thank you very much for your work and help.
Pepe Villasuso
Your Java Applets are of great use in showing elementary students some
of the basics of science. You are to be commended for your hard work
and
dedications.
Sincere thanks
Robert M. Craig
Talenetd and Gifted Coordinator
West Alexandria, Ohio USA
Hi Again.
First let me apologise for not responding sooner, but I was on
vacation.
Second, I would like to thank you for having sent the Source
Code, it
really helped alot...
Now it is my turn to help you out (if U want to), I made another
program
that simulated: ' Attwood's Machine', since you dont have it on the
list I
could send you a copy of it ..(it is in C though...)
Let my know if you want it or not...BTW it also uses RK4, but
it looks
diferent from your routine....
Anyway thank you very much.
On Fri, 18 Dec 1998, Fu-Kwun Hwang wrote:
>
>
> Joao Manuel Henriques wrote:
>
> > Hi.
> > I am a student of the University of Lisbon and I was a assigned
a task to
> > simulate the cyclotron.
> > It has been really hard to make something that actually resembled
a
> > cyclotron, but i still cant make the electron spin according to
the
> > frequency of the Voltage.
> > Can you please help me out?
> >
> > Here is what I need to know:
> > -I calculated a formula that calculates Theta, but the center
of the
> > circular movement is constant. In other words the Ray of the circunference
> > increases, but the center doesnt change like it should.
> > Can you tell me the formula to theta?
> >
>
> This is not the way I did it. There is a better way to do it:
> If you know the velocity V and force (F=qVXB) at time t,
> you will be able to calculate velocity at t+dt;
> If you know the position and velocity of a particle at time t,
> you will be able to calculate next position at time t+dt.
> Repeat the above loop, you will know the next position and velocity
at next
> moment t+dt;
>
>
> >
> > There is something else I want to ask.
> > Is there a possibility of you sending me the source code?
> > I know this is an unusual request, but it would really make
me understand
> > how the program really works. My source code is so complex that
not even I
> > can understand it, and above all it doesnt simulate the cyclotron
right.
> > I would be very gratefull if you could send it. I promise
I wouldn't
> > change the code and say that the program is mine. All I need to
know is
> > how you did it.
> >
> > Well, please e-mail me back with a response, preferably one
with the
> > reply i want to get.
> >
> > Thank you for your attention.
> >
> >
> >
Joao Henriques
> >
http://camoes.rnl.ist.utl.pt/~jmh
>
> The source code is attached with this e-mail. But you will need to
know about
> the
> Runge-Kutta method to understand the rk4 class.
>
Sir;
Enjoyed very much the physics
of light showing internal reflection, and
diffusion of the laser.
I look forward to examining more related Java applications, but a very
good
presentation.
Reg Coppicus
Nova Scotia, Canada