<Li> A uniform medium or homogeneous medium if its physical properties are unchanged at different locations in space </Li> <Li> An anisotropic medium if one or more of its physical properties differ in one or more directions </Li> <Li> An isotropic medium if its physical properties are the same in all directions </Li> <P> Absorption of waves means, if a kind of wave strikes a matter, it will be absorbed by the matter . When a wave with that same natural frequency impinges upon an atom, then the electrons of that atom will be set into vibrational motion . If a wave of a given frequency strikes a material with electrons having the same vibrational frequencies, then those electrons will absorb the energy of the wave and transform it into vibrational motion . </P>

The speed of a shallow-water wave is a function of the wavelength and/or the wave period