Why do spring tides happen twice a month

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

If you let go of the notebook after lifting it, will it move? how?

Frequency of electromagnetic waves that a radio station is assigned. what do you call this type of wave?