What is coefficient of friction?
The coefficient of friction (also known as the frictional coefficient) is a dimensionless physics value which describes the ratio of the force of friction between two bodies and the force pressing them together. The coefficient of friction depends on the materials used — for example, ice on metal has a low coefficient of friction (they slide past each other easily), while rubber on pavement has a high coefficient of friction (they do not slide past each other easily). Coefficients of friction of a tire on concrete may have a coefficient of friction of 1.7. Brake pad coefficients are generally between 0.3 and 0.7. Magnetically attractive surfaces can have very large friction coefficients, and glued or welded together surfaces have infinite friction coefficients. Coefficient of friction can vary depending on the type of material used for the brake rotor. Brake pads are typically concerned with dynamic coefficient of friction, or the coefficient of friction measured while the vehicle is
Article courtesy of The Marble Institute of America Stone used on commercial and residential floors should provide a safe walking surface in both wet and dry conditions. By measuring the coefficient of friction (COF), a quantitative number can be used to express the degree of slip resistance of a floor surface. When the coefficient of friction is measured from a resting position, it is called the “static coefficient of friction” (SCOF). When it is measured when the surfaces are in relative motion, it is called the “dynamic coefficient of friction”. Measuring the dynamic COF is difficult and requires a strict laboratory environment for accurate results. Almost all portable and laboratory meters measure only the static COF and most measuring devices (slip meters) refer to static COF. The higher the SCOF, the less slippery the surface. It is possible to have too high a SCOF; the surface can be too slip resistant and difficult to walk on. How is the coefficient of friction measured? There
Friction is the force resisting the relative motion of two surfaces in contact or a surface in contact with a fluid (e.g. air on an aircraft or water in a pipe). coffeccient of friction is a dimensionless scalar value which describes the ratio of the force of friction between two bodies and the force pressing them together. The coefficient of friction depends on the materials used; for example, ice on steel has a low coefficient of friction (the two materials slide past each other easily), while rubber on pavement has a high coefficient of friction (the materials do not slide past each other easily). Coefficients of friction range from near zero to greater than one – under good conditions, a tire on concrete may have a coefficient of friction of 1.7.
