What is swimming and why

Everyone has probably experienced this phenomenon - some things swim in the water and some go under. We explain to you what is heavier than water and what is lighter. So stay tuned if you've ever wondered why some things feel lighter and still sink like a stone and why others are heavier and swim at the top of the water.

The different densities of materials and substances are responsible for this. Every object and every material has a density. The well-known trick question: "What is heavier, a kilo of feathers or a kilo of lead?" Is probably familiar to everyone. Both are of course equally difficult, but the key point is density! For example, a metal object has a different density than a piece of wood or an air mattress. All materials are composed of the smallest particles, which are also called atoms or molecules. If these particles are very close together, the object is heavier than water, as is the case, for example, with a metal screw. In contrast: in an oil the particles are very far apart, so oil is lighter than water and floats on the surface of the water.

 

About physical relationships

All substances that have a lower density than water are lighter. The density of water is 1. The density of wood is between 0.1-0.8 - it is therefore lighter than water and thus floats on the surface of the water without sinking. Olive oil has a density of 0.6-0.9 and therefore stays on the surface of the water, you have probably already seen that in the kitchen ;-)

Materials such as concrete, sandstone and glass have a density of over 2 and sink to the bottom in the water because they are heavier. However, one and the same substance can also have a different density. Water, ice and water vapor actually consist of the same thing, only that water is liquid, ice is solid and water vapor is gaseous. In its liquid state, water has the unusual property of having a greater density than ice and water vapor. Therefore, ice cubes float in a glass of water and icebergs in the sea also float on the surface of the water, as you probably know or have already observed.

09.07.2020

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