When ocean waves pass through a narrow breakwater such as shown below, they diffract. The minima of the wave diffraction pattern will tend to become the places where the seaweed collects on the beach 60.0 m away. If you walk along the beach one morning and observe two piles of seaweed across from the breakwater, what is the wavelength of the waves hitting the breakwater overnight? On another day, if the beach is 20.0 m from the breakwater (still with one narrow opening of 2.00 m), what separation between the two seaweed piles are you going to observe? Consider that the wavelength of the waves is the same.
Breakwater
Seaweed
Beach