The term " speed " refers to the traction ( kinetic friction ) of performance surfaces : " fast " describes a slippery surface, and " slow " describes a higher-traction surface, like a gym floor.
22.
Can anyone direct me to research regarding the ratio of static friction and kinetic friction, i . e . I am interested in \ mu _ s : \ mu _ k . talk ) 20 : 04, 27 June 2012 ( UTC)
23.
This can be applied to static friction ( friction preventing two stationary objects from slipping on their own ), kinetic friction ( friction between two objects scraping / sliding past each other ), or rolling ( frictional force which prevents slipping but causes a torque to exert on a round object ).
24.
Both static and kinetic coefficients of friction depend on the pair of surfaces in contact; for a given pair of surfaces, the coefficient of static friction is " usually " larger than that of kinetic friction; in some sets the two coefficients are equal, such as teflon-on-teflon.
25.
Where F _ \ mathrm { f } is the force of friction exerted by the object and the inclined plane on each other, parallel to the surface of the plane, F _ \ mathrm { N } is the normal force exerted by the object and the plane on each other, directed perpendicular to the plane, and \ mu _ \ mathrm { k } is the coefficient of kinetic friction.
26.
Starting with F _ f = \ mu _ k F _ n, where \ mu _ k is the coefficient of kinetic friction and F _ n is the normal force, I got d \ tau _ f = r \ mu _ kgdm, where d \ tau _ f is the frictional torque, g is gravity, and r is the radius of mass element dm from the center of mass.
