The two solid COF can also vary considerably depending on friction or dry friction call is lubricated – a form of fluid friction. This may seem obvious, but there are some materials that COF remains the same regardless of the presence or absence of lubricant, such as steel on steel and polyethylene to Teflon.
The laws of the three laws of dry friction and Amontons “first and second friction
Amontons First Law “:” The friction force is directly proportional to the applied load. “For example, doubling the load of the friction force will also double – increases or decreases proportionately.
Amontons Second Law “:” The friction force is independent of the apparent surface of contact. Flat “areas like the face of a brick or smooth sheet steel, are just shots from the nerve endings in your fingers can detect.
All surfaces to form a row of peaks and valleys seen in the microscope, the peak height, which are determined by the type of material.
According to the law Amontons First, these peaks will be crushed or bent in proportion to the normal force, causing more or less at the peaks of friction contact. But if you extend a certain weight in a wider area, all they do is to reduce weight at any time under the pressure equation P = F / A, P pressure, F for force, and region.
The force is constant as the weight of the object in question does not change, meaning that changes in the surface, the pressure must also change with an inverse proportion. This means that less material will actually be in contact per unit area. This results in a lump sum equal to the force of friction the same weight and power, demonstrating the second law of Amontons. ”
Rubber tires and the second law of Amontons ”
Well, what about rubber tires? Good question. Amontons The second law “is an idealization which is more or less rigid and elastic. Traction apparent upper size tires can be attributed to the fact that the rubber is actually relatively slight elastic deformation to accommodate the geometry of the different soil conditions, and therefore be considered as an exception to this law. The most friction forces often provide elasticity is negligible compared with the amount of COF tape defined by the material. – Because the wider tires to compensate for the wear rate faster with more rubber COF distributing weight over a larger area! Contrary to popular belief, is the main reason for wider tires, not the width, in itself, provides more traction. For most practical purposes, the second law of Amontons “still stands.
Coulomb law of friction “dynamic friction is independent of sliding speed.” It’s simple and simply says that the rate at which two bodies move in relation to another is irrelevant in determining the kinetic friction force.
Posted in science | Tags: coefficient of friction, coefficient of static friction, drag force, dry friction, example of static friction, fluid friction, force of friction, friction coefficient, friction drive, friction force, frictional force, internal friction, rubber flooring, static friction and kinetic friction, types of friction
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