Ocean surface waves travel from a shallow region where their speed is vs into an adjacent deeper region where their speed is vd (vd>vs). The wave fronts approach the depth change head-on so refraction can be neglected; only partial reflection and transmission occur.
(a) Describe qualitatively how the amplitudes of the reflected and transmitted waves compare with the amplitude of the incident wave.
(b) Suppose the depth change is very small so that vd is only slightly greater than vs. Predict how the energy distribution between reflection and transmission in this case differs from the distribution when vd≫vs. Give reasons for your prediction.
(c) Explain, in non-mathematical terms, how the concept of “impedance” for water waves helps account for the trends you described in parts (a) and (b).