HKCEE Physics

1. Regulation of temperature in coastal cities. High specific heat capacity means need more heat energy from sun to reach same temperature than level of land. Therefore, land is hotter than air in daytime and so cooler air comes in diffusion to cool down land. At night, the same process occurs but in the reversed direction as water needs more time to cool than soil/land.

2. Hot water bottles for sleeping in winter. High specific heat capacity means a lot of energy has to be lost before the water bottle will cool down. This can provide a stable heat energy source for us and keep us warm. E.g. 1kg of water needs to dissipate 86kJ of heat energy in order to lower its temperature from 60 degrees celsius to 40, which is still quite warm for us.

3. Maintain Stable Environment for Coral Reefs and some marine animals. Coral reefs for example, can only live within a very narrow range of temperature, i.e. 26-28 degrees celsius. Without the high specific heat capacity of water, the seawater temperature cannot remain within the range and the coral reefs cannot survive!

Applications of water (because of the high specific heat capacity)
1. Area near sea has smaller temperature change in winter and summer.
2. Cool down car engine.
3. Regulate body temperature