The following applet simulated a famous pendulum wave.
The length of each pendulum is different so that the frequency of each pendulum is different by a fixed amount.
The frequency of the first one f1 and the difference between near by pendulum can be adjusted by slider.
Because the frequency is too faster to be observed by our eye, so the simulation show slow motion of the real wave by a factor of 100. (You can change time scale,too. Drag the slider to the right to make it faster.)

translate strings in simulation to different language format before download
Full screen applet or Problem viewing java?Add to exception site list
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
Download EJS jar file(1736.5kB):double click downloaded file to run it. (33 times by 22 users) , Download EJS source (17 times by 11 users) View EJS source

Check out youtube movie for pendulum wave