Assuming its "resting" is the place in the middle of the wave crest and trough, the distance between the crest and the middle line would be considered its amplitude. The height of a wave is the distance between the crest and the trough, and wavelength is the distance between two crests.
If we talk about mathematics and the science behind geography, east and west are directions that may represent infinitely. The reason why quantity exist is to measure and create scales on how far an object is from the origin or the point of locus.
These directions can be compared to a line in math which is an endless and limitless progress of points connected without a direction however, incorporating a specific direction could still represent a endless point of west; an endless point to east. Conclusively both are infinite and long unless determined and specified by a continouous measure.
The correct answer is differentiation.
Planetary differentiation can be defined as a process in which separation of different constituents of the planetary body takes place.They are separated based on their physical or chemical behavior, where the body divides into different layers: the less denser materials rise up to the surface and the more denser substance of the planet sinks.
Example: dwarf planets.