Ripple Tank
Overview:
Supplies:
Objectives:
Setup:
- Fill the tank with water so the paddles touch the surface of the water.
- Plug in and turn on the light overhead.
- Place white paper underneath the tank to act as a screen.
How to run the demo:
- Change the frequency of the oscillating pattern and whether the paddles are in phase or out of phase.
- Having the light strobe or be constant will make the pattern appear moving or stationary.
What’s Happening?
The ripple tank demonstrates the wave behavior of light. Spherical waves emanate from both paddles and expand outwards, and where they overlap you will have constructive or destructive interference. This is being demonstrated with water, but the same behavior can be observed with light. This can illustrate refraction and reflection, but also diffraction and interference.
Learn more: (external links)
PhET Interactive wave simulation: https://phet.colorado.edu/en/simulation/wave-interference
Video of a ripple tank (the first 2minutes are setup of a similar system, skip to 2:10 to see it in action)