When two waves of the same frequency and the same amplitude arrive at one point, they are superimposed, and their amplitudes are added giving rise to an "interference pattern."

• At certain points, the two incident waves vibrate in phase and ther total amplitude observed is greater than the amplitude of each individual wave. It is called constructive interference.
• At other points, the two waves vibrate out of phase and the total observed amplitude is smaller than the amplitude of each wave individually. This is called destructive interference.

Lines of maximum amplitude and minimum amplitude appear. These lines are called "fringes". These are rectangular (or equilateral) hyperbolas.

Click and drag the sensor on the surface of the water.