EJS version of Doppler effect (You can hear sound)

[Fu-Kwun Hwang]

This java applet show the Doppler effect.
Click inside the simulation region to select initial position for wave center.
While press down the mouse, drag the mouse to change the velocity for the wave source. (This is a moving point source)

The wave speed and the period of the wave (f=2*π/T) is adjustable by sliders.
If the source speed is smaller than wave speed. An ear gif image will appear in the simulation region(you can drag it to other position).
You will hear a sound click when the wave front pass the ear. (The frequency of the click sound is related to Doppler effect)

You will find wave pattern for shock wave when the source speed is larger than wave speed.
-*-

Embed a running copy of this simulation
<applet code='users.ntnu.fkh.dopplerxy_pkg.dopplerxyApplet.class' archive='http://www.phy.ntnu.edu.tw/ntnujava/ejsuser/2/ejs_dopplerxy.jar' name='dopplerxy3316' id='dopplerxy3316' width='645' height='377' mayscript=true><param name='draggable' value='true'></applet>
Embed a running copy link(show simulation in a popuped window)
<a href='http://www.phy.ntnu.edu.tw/ntnujava/msg.php?smfejs=3316' target='smfejs'>Run simulation</a>

Full screen applet or Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License

• Please feel free to post your ideas about how to use the simulation for better teaching and learning.
• Post questions to be asked to help students to think, to explore.
• Upload worksheets as attached files to share with more users.

Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!

The following is a flash demo

[j142]

Can you upload the sound of train or ringing bell instead of clicking sound?

we will be have  experience of frequencies change while we are at railway station.

[Fu-Kwun Hwang]

All the simulations I have created at this web site are ailable for offline use.
The above simulation was created with EJS 4.
You can click "get files for offline use" button and get the jar file.
You will find ejs source code if you unzip the jar file with any UNZIP program.
Load the source with latest EJS 4 and you can switch to any sound file (.wav format) you have.

However, it is still different from the experience in real life. 

[lookang]

dear Prof,

i am wondering, can make a scalarField that is for doppler effect?

i am thinking with a template of your codes, i can try to make
http://www.falstad.com/ripple/

with many options


currently, my attempt is not working

a summary of the codes is


for (i=0; i < number; i++)
{
 xscalar = xmin+(xmax-xmin)*i/number;
 for (j=0; j < number; j++)
 {
  yscalar = ymin+(ymax-ymin)*j/number;
  d[ i ][ j ]=Math.sqrt((xscalar-x)*(xscalar-x)+(yscalar-y)*(yscalar-y));
//sum [ i ][ j ]= A1*Math.cos(omega*t-k*d[ i ][ j ]);
//sum[ i ][ j ]= A1*Math.cos(omega/4*t);
sum[ i ][ j ]= A1*Math.cos(-k*d [ i ][ j ]);
}
}


Thanks! 

Embed a running copy of this simulation
<applet code='users.sgeducation.lookang.dopplerxywee01_pkg.dopplerxywee01Applet.class' archive='http://www.phy.ntnu.edu.tw/ntnujava/ejsuser/14019/ejs_dopplerxywee01.jar' name='dopplerxywee018556' id='dopplerxywee018556' width='701' height='500' mayscript=true><param name='draggable' value='true'></applet>
Embed a running copy link(show simulation in a popuped window)
<a href='http://www.phy.ntnu.edu.tw/ntnujava/msg.php?smfejs=8556' target='smfejs'>Run simulation</a>

Full screen applet or Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License

• Please feel free to post your ideas about how to use the simulation for better teaching and learning.
• Post questions to be asked to help students to think, to explore.
• Upload worksheets as attached files to share with more users.

Let's work together. We can help more users understand physics conceptually and enjoy the fun of learning physics!