Question

Ocean waves pass through two small openings in a breakwater. This time the openings are d = 21 m apart. You're in a small boat on a perpendicular line midway between the two openings, L = 80 m from the breakwater. You row x = 32 m parallel to the breakwater and find yourself in a region of calm water. What is the wavelength of the ocean waves if the calm water you encounter at x = 32 m is the second calm region on your voyage from the center line?

Answer 1

Use the same equation as is used for the diffraction of light by a double slit. (Young's experiment)

http://theory.uwinnipeg.ca/physics/light/node9.html