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

## Easy Java Simulations (2001- ) => Optics => Topic started by: Fu-Kwun Hwang on January 28, 2011, 09:40:59 am

 Title: Suposition of several waves Post by: Fu-Kwun Hwang on January 28, 2011, 09:40:59 am The following simulate suposition of several sinwaves (n=1-5).user can adjust wavelength, period, slit width and number of sources.Enjoy!   Title: Re: Suposition of several waves Post by: ahmedelshfie on January 28, 2011, 04:24:18 pm WOW, i like too much  the design of applet. Title: Re: Suposition of several waves Post by: lookang on January 31, 2011, 08:56:21 am hi prof!can make your ejs applet to allow to show this?reference:http://ngsir.netfirms.com/englishhtm/Diffraction.htmA wave spreads out (noticeable diffraction) when the size of the slit is comparable to or smaller than the wavelength.When waves reach a narrow slit, the water in the slit vibrates like a point source. The waves thus sent out from secondary sources along the slit are nearly in-phase when arriving any point in the forward direction. The diffracted wave resembles a circular wave with centre at the slit.(http://ngsir.netfirms.com/applets/diffraction/diffraction2.png) currently i think the ejs applet above only shows a circular source (i change it to n=1) at the slit width that spread in 180 degree which will occur when wavelength ~= slit width, that should be a lesser wave at the sides.(http://www.phy.ntnu.edu.tw/ntnujava/index.php?action=dlattach;topic=2082.0;attach=3837;image) i made slidth width = wavelength = 0.5, is should show lesser waves (represented perhaps by less intensity?) at the sidesA wave goes straight when the size of the slit is much larger than the wavelength.(http://ngsir.netfirms.com/applets/diffraction/diffraction1.png)currently i think the ejs applet above does not show this effect when wavelength << slit width(http://www.phy.ntnu.edu.tw/ntnujava/index.php?action=dlattach;topic=2082.0;attach=3839;image) Title: Re: Suposition of several waves Post by: Fu-Kwun Hwang on January 31, 2011, 03:42:06 pm I modified the above applet (add more constraints) so that it will be closer to the real case.About your request to generate something similar to the following image. (http://ngsir.netfirms.com/applets/diffraction/diffraction1.png)Do you think the above image is a real wave? I am not so sure!The intensity of diffracted wave should be much weaker than what has been shown in the above image.And I do not think you will find any pattern (as found in the animation at http://ngsir.netfirms.com/applets/diffraction/2X/Diffraction.htm).I will try to create one if you can show me a real experiment (video) which will generate pattern similar to the above image.   ;)  Title: Re: Suposition of several waves Post by: lookang on January 31, 2011, 04:58:15 pm interesting suggestion!i search the net and i found this