(a) Calculate the de Broglie wavelength (in m) of a 1.40 kg rock thrown with a speed of 4.50 m/s into a pond. m (b) Is this wavelength similar to that of the water waves produced? Explain. Yes, the wavelength of the water waves depends on the medium; they are strictly mechanical waves. No, the wavelength of the water waves depends only on the speed of the rock. No, the wavelength of the water waves depends on the medium; they are strictly mechanical waves. Yes, the wavelength of the water waves depends on the mass and speed of the rock.