Show the interference pattern between two point sources with the same frequency.



Teachable Topics:
  • Superposition
  • Sound and Music
  • Frequency


When multiple waves arrive at the same point in space at the same time, the will interfere with each other due to the principle of superposition. According to superposition, waves will add together at this point, resulting in either constructive or destructive interference.

Constructive interference is when the waves add together, resulting in a larger amplitude wave. This can be seen in the video where the waves are darkest (the peak of a wave) or lightest (the valley of a wave). Destructive interference is when the waves subtract, resulting in a smaller amplitude wave.


  • Ripple Tank


  • Set up the ripple tank so that two evenly spaced apart point sources will oscillate with the same frequency. Observe the pattern formed by the wave interference. Using a strobe light flashing at the same frequency as the point sources will make the waves appear stationary, allowing you to observe the interference pattern more clearly.