Friction
hideFriction is the force resisting the relative lateral (tangential) motion of solid surfaces, fluid layers, or material elements in contact. It is usually subdivided into several varieties:
Friction is not a fundamental force, as it is derived from electromagnetic force between charged particles, including electrons, protons, atoms, and molecules, and so cannot be calculated from first principles, but instead must be found empirically. When contacting surfaces move relative to each other, the friction between the two surfaces converts kinetic energy into thermal energy, or heat. Contrary to earlier explanations, kinetic friction is now understood not to be caused by surface roughness but by chemical bonding between the surfaces. Surface roughness and contact area, however, do affect kinetic friction for micro- and nano-scale objects where surface area forces dominate inertial forces.
For more information about Friction, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with friction
Friction force differences offer new means for manipulating nanotubes
Nanotechnology / Nanomaterials
Sep 15, 2009 |
4.5 / 5 (2) |
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(PhysOrg.com) -- Nanotubes and nanowires are promising building blocks for future integrated nanoelectronic and photonic circuits, nanosensors, interconnects and electro-mechanical nanodevices. But some fundamental ...
Bionanomachines: Proteins as resistance fighters
Aug 14, 2009 |
5 / 5 (2) |
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(PhysOrg.com) -- Friction limits the speed and efficiency of macroscopic engines. Is this also true for nanomachines? A Dresden research team used laser tweezers to measure the friction between a single motor ...
High levels of cycling training damage triathletes' sperm
Jun 29, 2009 |
5 / 5 (2) |
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The high-intensity training undertaken by triathletes has a significant impact on the quality of their sperm, the 25th annual conference of the European Society of Human Reproduction and Embryology heard today (Monday 29 ...
Fingerprints do not improve grip friction
Jun 12, 2009 |
2.4 / 5 (11) |
5
Fingerprints mark us out as individuals and leave telltale signs of our presence on every object that we touch, but what are fingerprints really for? According to Roland Ennos, from the University of Manchester, ...
Study of gecko feet leads to advances in the science of friction (w/Video)
Jun 04, 2009 |
4.3 / 5 (3) |
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(PhysOrg.com) -- Whether it’s driving on icy roads, rock climbing, or getting a better grip on a bat, the science of friction and adhesion plays a role—large and small—in many human activities. In a new research paper published ...
Get a grip! Blistering new evidence on why we have fingerprints
May 29, 2009 |
4 / 5 (11) |
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(PhysOrg.com) -- Fingerprints do not help primates grip, as previously thought, scientists have discovered. They actually reduce the friction needed to hold onto flat surfaces. Now Dr Roland Ennos and his ...
DNA gripped in nanopores
Nanotechnology / Bio & Medicine
May 14, 2009 |
not rated yet |
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Molecular biologists, including the cool dudes from CSI, use gel electrophoresis to separate DNA fragments from each other in order to analyze the DNA. A team of researchers under the leadership of Vici winner Serge Lemay, ...
Models present new view of nanoscale friction
Feb 25, 2009 |
4.8 / 5 (8) |
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(PhysOrg.com) -- To understand friction on a very small scale, a team of University of Wisconsin-Madison engineers had to think big.
'Fossil earthquakes' abundant
Space & Earth / Earth Sciences
Jan 28, 2009 |
3 / 5 (3) |
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Rocks formed only under the extreme heat and friction during earthquakes, called pseudotachylytes, may be more abundant than previously reported, according to new research focused on eight faults found in the Sierra Nevada. ...
Researchers see exotic force for first time
Jan 07, 2009 |
4.8 / 5 (28) |
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(PhysOrg.com) -- For the first time, researchers have measured a long-theorized force that operates at distances so tiny they’re measured in billionths of a meter, which may have important applications in ...
Nanocoatings boost industrial energy efficiency
Nanotechnology / Nanomaterials
Nov 18, 2008 |
4.9 / 5 (15) |
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Friction is the bane of any machine. When moving parts are subject to friction, it takes more energy to move them, the machine doesn't operate as efficiently, and the parts have a tendency to wear out over ...
