zaterdag 23 oktober 2010

Hondenwetenschap


Wetenschap die je zelf zou hebben willen uitgevonden. Een onderzoeksteam van de Georgia Institute of Technology berekende hoe hard een natte hond zich moet schudden om weer droog te worden:
They found, for example, that a labrador retriever shakes his body at a frequency of 4.3Hz while a small huski does it at 5.8Hz. Looking at the frequency difference, they realized that the shaking speed was connected to the radius of the animal's body. Water is attached to the dog by surface tension, they thought, and the sinusoidal shaking creates centripetal forces that ejects that water off the body. Therefore, the larger the dog's body radius (R) is, the stronger these forces are on the dog's skin. This means that smaller furry animals would have to shake faster to achieve necessary forces, which is why a mouse has to shake at 27Hz, while a cat does it at 6Hz. Looking at this data, they found out that the frequency had to be the R^0.75, with the "shake frequencies asymptotically approach 4Hz as animals grow in size."
Meer? Hier. Bekijk vooral ook het filmpje.

Het prentje: via fed by birds.

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