Search results
Results from the WOW.Com Content Network
Kinetic friction, also known as dynamic friction or sliding friction, occurs when two objects are moving relative to each other and rub together (like a sled on the ground). The coefficient of kinetic friction is typically denoted as μ k, and is usually less than the coefficient of static friction for the same materials.
Sliding may occur between two objects of arbitrary shape, whereas rolling friction is the frictional force associated with the rotational movement of a somewhat disclike or other circular object along a surface. Generally, the frictional force of rolling friction is less than that associated with sliding kinetic friction. [1]
Coulomb damping dissipates energy constantly because of sliding friction. The magnitude of sliding friction is a constant value; independent of surface area, displacement or position, and velocity. The system undergoing Coulomb damping is periodic or oscillating and restrained by the sliding friction.
Relative motion of tractive surfaces - a sliding object (one in kinetic friction) has less traction than a non-sliding object (one in static friction). Direction of traction relative to some coordinate system - e.g., the available traction of a tire often differs between cornering, accelerating, and braking. [8]
The load then starts sliding, and the friction coefficient decreases to the value corresponding to load times the dynamic friction. Since this frictional force will be lower than the static value, the load accelerates until the decompressing spring can no longer generate enough force to overcome dynamic friction, and the load stops moving.
The coefficient of kinetic friction, , is less than the coefficient of static friction for both ice and snow. [9] [10] The force required for sliding on snow is the product of the coefficient of kinetic friction and the normal force: =. [11]
where is the coefficient of friction and is the weight on the wheel. Usually the force needed to start sliding is greater than that needed to continue sliding. The former is concerned with static friction (also known as " stiction " [ 3 ] ) or "limiting friction", whilst the latter is dynamic friction, also called "sliding friction".
Frictional contact mechanics is the study of the deformation of bodies in the presence of frictional effects, whereas frictionless contact mechanics assumes the absence of such effects. Frictional contact mechanics is concerned with a large range of different scales.