Ripple tanks are really cool ways to explore the way a wave behaves under the influence of a perturbation.
They are fairly simple to make, and are usually available in college and school laboratories to render better understanding of the wave phenomenon.
How does it work ?
There is a usually an oscillating paddle( above– used to produce plane waves) or a point source/s ( below – used to produce circular waves ) which are actuated by eccentric motors, solenoids, etc + a shallow tank of water.
And that’s about it! One is ready to visualize wave phenomenon
Here are some of my favorite renditions of physical phenomenon on a ripple tank. Check sources for more. Enjoy!
1. Diffraction
2.Double slit experiment
3. Reflection
4. Refraction
5. Parabolic Reflectors
6. Doppler Effect
Doppler effect is the increase (or decrease) in the frequency of sound, light, or other waves as the source and observer move toward (or away from) each other.
If we have a speaker that is moving to the right (see animation above), if you are standing infront of the speaker you will hear a shorter wavelength- higher frequency sound and if you are standing behind the moving speaker, you will hear a longer wavelength – lower frequency sound.
We experience the Doppler effect everyday whenever a car whizzes past us. Here’s a demo:
** Source videos : Educational Services Inc-1964 and Aerodynamic generation of sound