Question

At what water depth will a deep-water wave with a wavelength of 40 meters begin to "feel bottom"? 5 meters 15 meters 20 meters 10 meters

Answer 1

The answer is 20 meters would be the water depth started to feel bottom. This is half of the wavelength. The reason behind this is the wave travels half or the partial of the wavelength underneath the surface. For that reason that is where the wave would be starting to feel the ground.