The force of ice
Ice
If a plastic container of water is frozen, the ice expands and the plastic bulges outwards. If not enough space is provided, the container will split under the force of the expanding ice. If the container is glass, you know what would happen then! Yes, the force of the molecules rearranging themselves within the ice will crack the glass - an enormous force is exerted. A similar thing would happen with the water in your car radiator or with water pipes which freeze with serious results. In geology, water freezing in cracks in rocks expands the cracks and can even split rocks. This is an important type of weathering in highland areas where night and day temperatures vary above and below 0°C. Some plants are also affected by the force of freezing water. The cells contain water and, as the water freezes, it expands, breaking the cell walls. That's why some plants, such as tomatoes, cannot survive when the temperature goes below freezing. Other plants have more flexible cell walls and these are said to be frost hardy.
Freeze drying Icebergs
The melting point of ice is lowered under pressure. This has an important application in ice skating. An ice skating blade has a very small surface area so the weight of the skater exerts a high pressure. This means that the ice melts under the blade, the skater glides on water, then the ice refreezes behind the skater as the pressure is reduced.
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