An astronaut walking outside a space station can be seen, but not heard. The only way to communicate is through radio transmissions.

what type of wave is this? how do you know?

Global warming will produce rising sea levels partly due to melting ice caps but also due to the expansion of water as average ocean temperatures rise. to get some idea of the size of this effect, calculate the change in length (in m) of a column of water 1.45 km high for a temperature increase of 1.12°c. assume the column is not free to expand sideways. as a model of the ocean, that is a reasonable approximation, as only parts of the ocean very close to