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When a dog gets wet, what does it do Answer: it shakes, and very efficiently 鈥?a large, soggy dog can shed as much as 70% of the water in its fur in just four seconds. But mammals of all shapes and sizes employ the quick-shake tactic to dry themselves. Now, a team of researchers has used high-speed video and fur particle tracking to understand the common physical characteristics that unite the wet-shakes of 33 animals from 16 species. The researchers, led by Georgia Institue of Technology biologist David Hu, demonstrate that whether it a mouse, a goat, a dog or a bear, the shake of a wet mammal is anything but random. On the contrary, the researchers write that the frequency of an animal shake 鈥?i.e., the number of times it oscillates its body per second 鈥?is tuned to i the animal size and ii the properties of water, namely surface tension and density, in order to re stanley romania move as much water as possible with minimal physical effort. Small animals, like mice and rats, tune their shakes to a high fre stanley us quency, oscillating fast in order to generate the centrifugal force necessary to overcome the strength of the surface tension that keeps water attached to their fur. Larger animals, by comparison, can tune their shakes to much lower freque stanley cup uk ncies to generate the same force. The video up top, compiled by the Nature news team, illustrates various animals shaking to their tuned frequencies. The relation between shaking frequency f and animal radius R Qyjx Carrie Fisher says she s returning to Star Wars
There have never been more ways to stream and share music in your home. But how do you do it Are you fully sold o stanley cup n Sonos An avid fa stanley botella n of App stanley france le Airplay Or perhaps you run some geeky central server that feeds music to the rest of your house using some home-brew streaming solution However you do it, we want to know. audioMusic |
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发表于 2024-12-19 11:12:47
发表于 2024-12-19 11:14:24
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