# NTNUJAVA Virtual Physics LaboratoryEnjoy the fun of physics with simulations! Backup site http://enjoy.phy.ntnu.edu.tw/ntnujava/

## JDK1.0.2 simulations (1996-2001) => kinematics => Topic started by: Fu-Kwun Hwang on January 29, 2004, 03:10:12 pm

 Title: Simple Harmonic Motion and Uniform Circular Motion Post by: Fu-Kwun Hwang on January 29, 2004, 03:10:12 pm The force for a spring with displacement $\vec{x}$, spring constant k is $\vec{F}(x)=-k\vec{x}$ (Hook's Law).From Newton's law $\vec{F}=m \vec{a}=m \frac{d^2 x}{dt^2}$So $m \frac{d^2x}{dt^2}=-k x$.The solution of the above equation is $x=A \sin\omega t$. Since $\frac{dx}{dt}= A \omega \cos\omega t$, $\frac{d^2x}{dt^2}= -A \omega^2 \sin\omega t=-\omega^2 x$So $\omega=\sqrt{\frac{k}{m}}$. If the spring is moved away equilibrium position, it will move with displacement similar to $x=A \sin\omega t$, which is called simple Harmonic motion (SHM).The following applet shows relation betweeb simple harmonic motion and spring motion.$\frac{x^2}{a^2}+\frac{y^2}{b^2}=1$, $x(t)=a*\sin(\omega t), y(t)=b*\cos(\omega t)$The uniform circular motion is intimately related to a simple harmonic motion. If we were to look at a side view of the uniform circular motion on a thumbtack stuck on a rotating table, we would see the thumbtack oscillate in simple harmonic motion.Press Start to begin the animation.The black dot will move in uniform circular motion.Watch and find out the relation between uniform circular motion and simple harmonic motion.Press left mouse button to suspend the animation, press it again to resume.Did you find out the frequency of the uniform circular motion?The red arrow represents the velocity of the black dot.The yellow arrow and the blue arrow are components of the above velocity vector.Did you know when the thumbtack has maximum velocity ?If you click the left mouse button within the dark-gray area , and drag the mouse button left/right,you can rotate the circle about the vertical axis. (sample picture) You can rotate the circle 90 degree => side view of the motion.( This feature was added as a request from B. Surendranath Reddy.)[youtube=SZ541Luq4nE]The above clip is actually adopted from "The mechanical universe" series.[youtube=cD2KdK2GSvw] Title: topic148 Post by: on January 30, 2004, 11:30:52 am Subject:  your webpage Date:     8 Feb 99 16:40:40 PST From:     shefali oza To:       hwang@phy03.phy.ntnu.edu.tw 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) Title: topic148 Post by: on January 30, 2004, 11:31:14 am Subject:  your webpage Date:     Mon, 8 Feb 1999 20:55:47 EST From:     Bananas337@aol.com To:       hwang@phy03.phy.ntnu.edu.tw 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 Title: topic148 Post by: on January 30, 2004, 11:46:35 am Subject:  Applets Date:     Thu, 22 Apr 1999 18:20:15 +0100 From:     "Anthony Vinters" To:       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 Title: topic148 Post by: on January 30, 2004, 11:47:33 am Subject:  Re: Applets Date:     Mon, 26 Apr 1999 23:44:29 +0100 From:     "Anthony Vinters" To:       "Fu-Kwun Hwang" 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. Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: Duncan McLellan on February 21, 2005, 09:42:05 pm I teach Physics to 16-19 year old students and I have already used your SHM Applets in class using a data projector.  They are excellent.  Is there anyway in which I can download them and run them off our network? Title: topic148 Post by: Fu-Kwun Hwang on February 22, 2005, 09:24:37 am May be you did not notice that there is a button at the end of the first message labeled "GET APPLET FILE". Press that button and files related to the applet will send to your email address automatically and you can use it offline. Title: topic148 Post by: Mick on October 08, 2005, 09:07:17 am Hi this is really cool. i like the red yellow and blue vectors.  :shock:Is it possible i can get the Java source code for this app? I would like to see if i can do something similar but with different shapes. not just circles, but cams and trilobes and ellipsesI be happy to post my changes back to the forum :D Title: topic148 Post by: Nat Hager III on January 21, 2006, 01:41:48 am I downloaded the applet for off-line use, but the fonts are unreadible.  Can you tell me what I'm doing wrong?Nat Hager Title: topic148 Post by: Fu-Kwun Hwang on January 23, 2006, 08:42:14 am Usually the zip file cantains more than one html files.Index.html is the Chinese version, and other html files are for different language version.Please check out other html files.Fu-Kwun :-) Title: topic148 Post by: Physics88 on January 24, 2006, 08:23:26 pm Thanks to all of the people who designed this web site.My term homework was physics simulations and I found everything I wanted in this site.Thanks again. Title: topic148 Post by: Fu-Kwun Hwang on January 25, 2006, 01:06:16 pm You are welcomed! :-) Title: Thanks Post by: mma943 on December 14, 2006, 08:50:53 pm Thanks for this topic Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: scotbilt on November 13, 2007, 12:03:56 pm Dear Fu-Kwun Hwang,I am sorry for trying to download so many applets in such a short time frame.  I am a physics student and quite near finishing a degree to teach high school natural sciences.  These applets will be very useful to me in the classroom later in my career.  Also, in my Physics for Teachers course we have to teach 50 minute classes every week and a half so it is nice to have these for demo purposes.  Thanks very much for all your hard work, time, and consideration,Scott Biltoft Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: Fu-Kwun Hwang on November 13, 2007, 02:20:03 pm Because there are so many users visiting our server everyday. In order to reduce the web traffic load so that everybody can access the resource without too much delay. We ask user to wait at least 3 minutes for the next request. It should be enough for normal use and we believe user should at least read the message or play with the simulation for a while before user request to download it. Actually, we have found many users request our server to send too many simulations to their email account. The mail quota was  reached before we send all the simulations. And the email was bounced back to our server and increased the server load a lot. (Especially for simulations created with EJS -- The file size of EJS libraries are near 2M.) Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: ajayng on December 09, 2007, 02:51:36 am  >:(i cant see image of shm file Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: Fu-Kwun Hwang on December 09, 2007, 10:06:54 am It is not an image, it is a java simulation. I think it is because your browser did not support java. Please download Java Run time (http://www.java.com/en/download/manual.jsp)  from sun's web site. Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: merryjman on December 10, 2007, 01:51:23 am I am a physics teacher in Baltimore, Maryland USA.  I have used many of these applets in my classroom with great success.  Thank you for this wonderful resource!! Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: Fu-Kwun Hwang on December 10, 2007, 11:13:38 pm You are welcomed. I am glad to hear that our simulations are helpful. I got my Ph. D. from University of Maryland (College Park) many years ago. So I have been to Baltimore several times.  :o Please do not hesitate to give me whatever suggestions you might have, to improve our applets and make them better for physics teaching and learning. Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: dgpdx on February 10, 2008, 11:50:42 am Hello. I just discovered this site and would like to use your Java source code as an example for making my own simulations. I pressed the button asking for the files to sent to me and they were. When I look at the .class files sent to me, they are only interface files, there is no code in them. Is it possible to get the actual code as well?Thank you,don Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: Fu-Kwun Hwang on February 10, 2008, 02:45:28 pm You should have received the source code now. Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: dgpdx on February 11, 2008, 04:23:05 am Quote from: Fu-Kwun Hwang on February 10, 2008, 02:45:28 pmYou should have received the source code now.I have, and thank you very much!--don Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: balques on July 28, 2008, 12:56:18 am Hi,I would also like to use your code for circular motion for another java project I am currently working on. Could you please send me the code if you don't mind?Thank you in advance Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: Fu-Kwun Hwang on July 28, 2008, 11:14:44 am I just upload the source code as attachment for the first posted message.shm.java is the code for the applet, spring.java is the code for drawing the spring. Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: balques on July 28, 2008, 02:32:02 pm Quote from: Fu-Kwun Hwang on July 28, 2008, 11:14:44 amI just upload the source code as attachment for the first posted message.shm.java is the code for the applet, spring.java is the code for drawing the spring.Thank you very much. It was very helpful  :) Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: abdelwahab on October 24, 2008, 09:00:20 pm Dear  Fu-Kwun Hwang I would like to express my Admiration with this animation And would like to ask you to give me the permision to put it in my web site. with best regards Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: Fu-Kwun Hwang on October 24, 2008, 09:24:24 pm You are welcomed to do for non-profit educational purpose and add link back to this web page. :-) Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: super nerd dude on October 30, 2008, 06:37:41 am WOAH this is the best thing in my life im dedicating my life to it i luv it so much where can u download it from i want to play it everyday for the rest of my life thank u fukwunwang Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: dagudelo on November 04, 2008, 03:16:02 am Dear Mr Fu-Kwun Hwang, Im Diego from Colombia,and i just want to say thank you for the great work that you do. If i could help you in the tranlsation of your work to Spanish, it will be a pleasure for me. i will expand your knowledge in the classrooms of Medellin, Antioquia, Colombia, and i hope you can keep your work to help the education in the world. See you Mr  Fu-Kwun Hwang. With very best wishes, , Diego Esteban Agudelo. Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: etreasure on April 23, 2009, 01:40:00 am can u please send me the source code for circular motion, i just want to rotate a circle on an orbit. please help me. pl. send the source code at etreasure@rediffmail.comthank in adv, Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: Fu-Kwun Hwang on April 23, 2009, 06:10:32 am The source code is available as attached file (link at the end of the first message body).Please help yourself and download it by yourself (just click the link!). Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: dipa0493 on January 27, 2011, 10:04:53 am Just wanted to say thanks for this great animation, it has helped my understanding greatly!  Hello from New York, USA! Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: Fu-Kwun Hwang on January 28, 2011, 08:03:03 am You are welcomed. I hope you can enjoy the fun of physics as I do! (or even more) Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: boskom on May 22, 2011, 03:58:06 pm Quote from: dipa0493 on January 27, 2011, 10:04:53 amJust wanted to say thanks for this great animation, it has helped my understanding greatly!  Hello from New York, USA!I wouldn't have said it better myself.. hello from Zagreb, Croatia   :) Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: boskom on May 24, 2011, 02:50:53 am Quote from: etreasure on April 23, 2009, 01:40:00 amcan u please send me the source -*- for circular motion, i just want to rotate a circle on an orbit. please help me. pl. send the source code -*-thank in adv,I don`t know why, but my mail is returning from yours  ??? ??? Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: arame08 on August 10, 2011, 12:30:28 pm Is it possible i can get the Java source code for this app? I would like to see if i can do something similar but with different shapes. not just circles, but cams and trilobes and ellipses.-*- Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: Fu-Kwun Hwang on August 10, 2011, 01:58:39 pm The source code is available as attached file under the first message (where you saw the applet).Please download it by yourself if you really need it. :) Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: lstrejcek on January 14, 2012, 12:25:37 am Does anyone know if there is an equivalent form of motion but in three dimensions? If so, how would this look? Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: Fu-Kwun Hwang on January 14, 2012, 11:14:48 am Are you talking about circular motion in 3D (http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=6.0) or Spring motion in 3D (http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=614.0)?You are welcomed to check out the above URLs! ;D Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: wyatt on June 29, 2012, 11:19:55 pm can read the text Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: Fu-Kwun Hwang on June 30, 2012, 11:14:49 am It seems to be fine with my browser. Could you give me a snap-shot of your browser so that I can understand what might be the problem. Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: tookkatababi on September 29, 2012, 12:48:03 pm  ;D ;D ;D Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: ndpdarshana on December 24, 2012, 01:50:53 pm Can I get this source code please??? Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: ndpdarshana on December 24, 2012, 01:51:43 pm Can I get this source code please??? -*- Title: Re: Simple Harmonic Motion and Uniform Circular Motion Post by: Fu-Kwun Hwang on December 26, 2012, 07:25:11 am It is available as attached file under the top post.Please download it by yourself if you really need it.