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Monday, January 10, 2011

Ejs Open Source Ripple Tank Interference Model java applet « on: January 09, 2011, 12:20:50 AM »

Ejs Open Source Ripple Tank Interference Model java applet
« on: January 09, 2011, 12:20:50 AM »
ripple tank with hints added for 2 cases.
Case 1:
When the sources are in phase, λ = 0
condition for constructive interference: |S1P-S2P| = m λ, where m = 0, 1, 2, ...
condition for destructive interference: |S1P-S2P| = (m + 0.5) λ, where m = 0, 1, 2, ...

Case 2:
When the sources are in anti-phase, λ = 180 degree
condition for constructive interference: |S1P-S2P| = (m + 0.5)  λ, where m = 0, 1, 2, ...
condition for destructive interference: |S1P-S2P| = m λ, where m = 0, 1, 2, ...



ripple tank with added pen paper representation to aid transfer of learning to traditional assessment


NRF-MOE eduLab001 OpenSourcePhysics (OSP) project with Ripple Tank Innova Junior College, version 05 January 2012


13 Feb 2011 Screen shot of Ejs Open Source Ripple Tank Interference Model java applet to achieve the interference pattern at P ( move P to the edge screen x = 1.0) and move S1 and S1 to new position by lookang

13 Feb 2011 Screen shot of Ejs Open Source Ripple Tank Interference Model java applet by lookang



31Jan 2011Screen shot of Ejs Open Source Ripple Tank Interference Model java applet by lookang
Screen shot of Ejs Open Source Ripple Tank Interference Model java applet by lookang

Screen shot of 3D effect of interference under visualization surface plot

screen shot of example of incoherence f = 2 Hz =! f2 = 1 Hz, power of new remixed applet by lookang

Ejs Open Source Ripple Tank Interference Model java applet a remix from Interference Model: Ripple Tank written by Andrew Duffy http://www.compadre.org/osp/items/detail.cfm?ID=9989

http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=2067.0


http://en.wikipedia.org/wiki/Ripple_tank
http://en.wikipedia.org/wiki/File:Simple_ripple_tank.svg#globalusage by Cryonic07
A small 650W incandescent light source was mounted about one meter above the tank, and the ripples projected on the screen were photographed from the side (see lower picture on the right) using a high-speed video camera from http://livephoto.rit.edu/LPVideos/ripple/.
http://livephoto.rit.edu/LPVideos/ripple/Ripple_Tank_Waves_1.mov
a video suitable for video analysis using tracker?


In physics and engineering, a ripple tank is a shallow glass tank of water used in schools and colleges to demonstrate the basic properties of waves. It is a specialized form of a wave tank. The ripple tank is usually illuminated from above, so that the light shines through the water. Some small ripple tanks fit onto the top of an overhead projector, i.e. they are illuminated from below. The ripples on the water show up as shadows on the screen underneath the tank. All the basic properties of waves, including reflection, refraction, interference and diffraction, can be demonstrated.
Ripples may be generated by a piece of wood that is suspended above the tank on elastic bands so that it is just touching the surface. Screwed to wood is a motor that has an off centre weight attached to the axle. As the axle rotates the motor wobbles, shaking the wood and generating ripples.




Full screen applet with hints
Full screen applet with pen paper representation
Full screen applet
kindly hosted in NTNUJAVA Virtual Physics Laboratory by Professor Fu-Kwun Hwang http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=2067.0 alternatively, go direct to http://www.phy.ntnu.edu.tw/ntnujava/index.php?board=28.0 Collaborative Community of EJS (Moderator: lookang) and register , login and download all of them for free :) This work is licensed under a Creative Commons Attribution 3.0 Singapore License
Author: Andrew Duffy, Juan M. Aguirregabiria and lookang



Description adapted from the original by Andrew Duffy
Interference in Two Dimensions of 2 source
With this simulation, you can explore the interference pattern that results from the superposition of two sources of waves. The simulation models what happens
a) two speakers, emitting sound waves;
b) two oscillating bobbers or dippers in a water tank, producing water waves;
c) two light sources, so the interference is with two light waves.

In the simulation,
1) red regions (depending on the type of visualization selected) are areas where the net displacement is positive (such as when two peaks overlap)
2) blue regions are areas where the net displacement is negative (such as when two troughs overlap).
3) In the black regions, the net displacement is zero, or close to zero.


To understand this pattern, we use the idea of the path-length difference, S1P - S2P. There is a movable blue-point P in the simulation. The path-length difference (∆L) for this point is the distance the point is from one of the sources minus the distance the point is from the other source, or simply S1P - S2P. These distances are expressed in units of the wavelength λ.
When the sources send out waves that are in phase with one another, the waves will interfere completely constructively when the path-length difference is an integer number of wavelengths, and they will interfere destructively when the path-length difference is an integer number of wavelengths, plus half a wavelength. We can express this in the form of equations.
When the sources are in phase
condition for constructive interference: ∆L = m λ, where m = 0, 1, 2, ...
condition for destructive interference: ∆L = (m + 0.5) λ, where m = 0, 1, 2, ...


changes made

1 redesign layout and color scheme
2 add v and lambda slider controls
3 add time to show the progress for student to use v to calculate how much the wave move
4 add the 4 types of visualization
5 add the 10 mode of color visualization
6 add legend, suspect buggy but will try to activate it for relation learning to the visualization meaning of color
7 add S1 and S2 y displacement as vertical bar for understanding of phase difference at the sources S1 and S2
8 add y1 and y2 and y1+y2 for the y displacement for understanding of superposition of point P
17Jan2010
9 added coherence and incoherence check-box for exploring what if scenario for exploring in-depth the meaning of incoherence.
incoherence here refer to v=!v2 || f=!f2 || lambda=!lambda2
31January 2011
10 added screen effects (instantaneous patterns and average intensity patterns)  of the interference patterns for both coherent and incoherent sources fromhttp://www.cabrillo.edu/~jmccullough/Applets/OSP/Oscillations_and_Waves/waves_interference.jar by  Juan M. Aguirregabiria. now it is very easy to visualize the meaning of coherent sources. Smiley


10 February 2011
11 add check box to visual true S1, S2 and P bar values
12 add check box for visual instant and average pattern of the end of the screen for relating to future cases of interference as such light waves
13 made S1 and S2 show when radio buttons are selected
14 fix a bug on the S1 and S2 bar with phase is change
15 made the area to display top view of ripple tank bigger to solve the bug of a line showing
16 made some animated gif to others to use here http://weelookang.blogspot.com/2011/01/ejs-open-source-ripple-tank.html

Based on a rough idea i had some years ago :)
http://www.scribd.com/doc/46322449/Weelookang-Conceptual-Design-ProjectV1 p 11
the real difference today is i can make interactive java applet standing on the giants of Open Source Physics community instead of the conceptual paper i did which is pretty much just struck at the an idea stage.

http://www.seab.gov.sg/aLevel/20102011Syllabus/9646_2011.pdf
SECTION lV WAVES Superposition
(f) show an understanding of the terms interference and coherence.
(g) show an understanding of experiments which demonstrate two-source interference using water, light and microwaves.

Thanks to Andrew Duffy for his source original codes
and Fu-Kwun Hwang for this fantastic CoP forum
Paco for Easy Java Simulation
Wolfgang for Open Source Physics !
Juan M. Aguirregabiria for his screen patterns codes instantaneous patterns and average intensity patterns

and many others whom i have not met but have learn for the source codes and simulation!


What is a Two-Source Interference (Ripple Tank)?
An example of two-source interference can be observed in a ripple tank.

(Fig. 1) Two dippers S1 and S2 are attached to the vibrator of the ripple tank.
1.    Two dippers S1 and S2 are attached to the vibrator of the ripple tank. (Fig. 1)

2.    Each dipper, when oscillates vertically, generates circular waves. (Fig. 2)
Fig. 2 show Source S1 that creates a circular waves







Fig. 2 show Source S2 that creates a circular waves
3.    When the two waves meet, they interfere where each dipper's generated circular waves which superposition with one another.
resultant wave form due to the superposition of each wave generated by S1 and S2.
1 to 3 in animation would look like this.
Source S1 that creates a circular waves
Source S2 that creates a circular waves
resultant wave form due to the superposition of each wave generated by S1 and S2

4.    Between the two dippers, a stationary wave is formed due to constructive and destructive interference
stationary wave is formed in between S1 and S2
stationary wave is formed in between S1 and S2 (look closely at the wave formation in between S1 and S2
5.    When normal white light shines on the ripple tank with the interference pattern
resultant wave form due to the superposition of each wave generated by S1 and S2 in Black and White due to light shine through the water ripple tank on a piece of background position below the ripple tank
resultant wave form due to the superposition of each wave generated by S1 and S2 in Black and White due to light shine through the water ripple tank on a piece of background position below the ripple tank
6.    The positions where the waves meet that cancel out are called nodes, it is rather difficult to see so i will explain in terms of a spectrum visualization as always green due to (eg. peak meet trough) destructive interference occurs (i.e. source waves arrive in anti-phase)
the green parts are called nodes where the 2 waves meet destructively to create zero displacement
7.    The anti-nodes will be alternating between bright (eg. peak meet peak ) and dark (eg. trough meet trough) for White and Black visualization or Red (eg. peak meet peak ) and Blue (eg. trough meet trough)  due to constructive interference (i.e. source waves arrive in phase). note that (peak meet peak ) and (trough meet trough) is constructive.

8.    The lines passing through a series of nodes are called the nodal lines

nodal lines and antinodal lines picture by leongster
9.    The lines passing through a series of anti-nodes are called the antinodal lines

10. for example, the distance between point P and S1, S1P = 4.5 λ and S2P = 4.5 λ, therefore path difference between the sources,  S2P –S1P = 0 for a constructive (trough meet trough) dark interference.
S1P = 4.5 λ
S2P = 4.5 λ
S2P –S1P = 0.
11. for example, the distance between point P and S1, S1P = 4.0 λ and S2P = 4.0 λ, therefore path difference between the sources,  S2P –S1P = 0 for a constructive (peak meet peak) bright interference.

S1P = 4.0 λ
S2P = 4.0 λ

S2P –S1P = 0
12. for example, the distance between point P and S1, S1P = 5.0 λ and S2P = 5.5 λ, therefore path difference between the sources,  S2P –S1P = 0.5 λ for a destructive interference.
S1P = 5.0 λ
S2P = 5.5 λ
|S1P –S2P| = 0.5 λ
13. for example, the distance between point P and S1, S1P = 4.5 λ and S2P = 5.0 λ, therefore path difference between the sources,  S2P –S1P = 0.5 λ for a destructive interference.
S1P = 4.5 λ
S2P = 5.0 λ
|S1P –S2P| = 0.5 λ
In Conclusion, when the sources are in phase
condition for constructive interference: ∆L = m λ, where m = 0, 1, 2, ...
condition for destructive interference: ∆L = (m + 0.5) λ, where m = 0, 1, 2, ...

You can explore the applet for the cases when  the sources are in anti-phase yourself !

Enjoy!!


adding more pictures
screen shot of the ejs applet of a ripple tank interference pattern by lookang


animated gif of the ejs applet of a ripple tank interference pattern with the 2 sources in the middle by lookang

screen shot of the ejs applet of a ripple tank interference pattern represented in light (S1max+S2max) and dark(S1min+S2min) visual by lookang

 animated low quality grid gif of the ejs applet of a ripple tank interference pattern with the 2 sources in phase (phase difference=0) at the left side by lookang

 animated high quality interpolated gif of the ejs applet of a ripple tank interference pattern with the 2 sources in phase (phase difference=0) at the left side by lookang


animated low quality grid multi-color interpolated gif of the ejs applet of a ripple tank interference pattern with the 2 sources in phase (phase difference=0) at the left side by lookang

animated gif of the ejs applet of a ripple tank of S1 source alone on the left side by lookang 

 animated gif of the ejs applet of a ripple tank of S2 source alone on the left side by lookang 


 animated gif of the ejs applet of a ripple tank interference pattern with the 2 sources in anti-phase (phase difference=180 degree or PI radian) at the left side by lookang



http://www.youtube.com/watch?v=QB-RU2mygWk


http://www.youtube.com/watch?v=nHK1aRpKKWw




other great simulation is http://phet.colorado.edu/en/simulation/wave-interference
http://phet.colorado.edu/en/simulation/wave-interference
Like: a lot of possibilities
very complex and realistic

http://www.cabrillo.edu/~jmccullough/Physics/Interference_Wave_Nature.html
collection of good applets


contribution to Wikimedia

descDate Name Thumbnail Size User Description
12:10, 20 October 2011RippletankpointS1P4.5-5.0.png (file)23 KBLookang
12:10, 20 October 2011RippletankpointS2P5.5-5.0.png (file)23 KBLookang
12:10, 20 October 2011RippletankpointS1S2P5.5-5.0.png (file)26 KBLookang
12:10, 20 October 2011RippletankpointS2P4L.png (file)22 KBLookang
12:10, 20 October 2011RippletankpointS1S2P4L.png (file)26 KBLookang
12:10, 20 October 2011RippletankpointS1P5.5-5.0.png (file)23 KBLookang
12:10, 20 October 2011RippletankpointS2P.png (file)23 KBLookang
12:10, 20 October 2011RippletankpointS1S2P.png (file)26 KBLookang
12:10, 20 October 2011RippletankpointS1P4L.png (file)22 KBLookang
10:48, 20 October 2011RippletankpointP.png (file)22 KBLookang
10:48, 20 October 2011Rippletankleongster.png (file)29 KBLookang
10:48, 20 October 2011Nodalandantinodallines.png (file)143 KBLookang
10:48, 20 October 2011Rippletanksource1plus2supositionBnW.gif (file)223 KBLookang
10:48, 20 October 2011Rippletankstationaraves1ns2.png (file)36 KBLookang
10:48, 20 October 2011Rippletanksource1plus2superpositionBnW.png (file)17 KBLookang
10:48, 20 October 2011Rippletanksource1n2stationarywave.gif (file)526 KBLookang
10:48, 20 October 2011Rippletanksource2.gif (file)150 KBLookang
10:48, 20 October 2011Rippletanksource1plus2suposition.gif (file)223 KBLookang
10:48, 20 October 2011Rippletanksource1.png (file)9 KBLookang
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