The of ocean water depends on the amount of salt dissolved in it and its temperature.

if you already have the answer to (a), then just work out how many periods there are in 1 minute, and that's the answer to (c).

a high pressure system is a dense air mass that is usually cooler and drier than the surrounding air. a low pressure system is a less dense air mass that is usually wetter and warmer than the surrounding air.

in general, areas that experience high atmospheric pressure also experience fair weather. low pressure systems can cause the formation of clouds and storms. air usually flows from areas of high pressure to areas of low pressure..