Every liquid has the same density

Properties of liquids and gases

Prandtl - Guide to Fluid Mechanics pp 13-41 | Cite as

  • Herbert Oerteljr.
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Liquids differ from solid bodies in that their particles are easy to move. While with solid bodies finite, sometimes very considerable forces are necessary to change their shape, the forces required to change the shape of liquids disappear completely if there is sufficient time for the shape change. In the case of rapid changes in shape, resistance also occurs in liquids, but this disappears very quickly after the movement has ended. One calls the property of liquids to offer resistance to change of shape, toughness. The toughness will be discussed in detail in Section 4.2. In addition to the usual, easily mobile liquids, there are also very viscous liquids whose resistance to change in shape is considerable, but also disappears again when at rest. Starting from the tough state, all phase transitions to the (amorphous) solid body are possible. Heated glass e.g. B. goes through all possible transitions, with asphalt and similar materials they occur at normal temperatures. For example, an overturned bin of asphalt will run out in a few days or weeks, depending on the temperature. The spilled mass forms a flat cake. Although this continues to flow, one can step on it without making any noticeable impressions. However, impressions are formed when standing for a long time. When working with a hammer, the mass splinters like glass.

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© Springer Fachmedien Wiesbaden 2012

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