Friction is exerted when an object sliding over a surface and its formula Ff =miu times normal force miu is the coefficient of friction Velocity is how fast a body moves with in direction and velocity =displacement over time
Friction is typically unrelated to speed. When the surfaces start to melt or otherwise change because of heat build up or inability to follow the surface then things will change.
Friction is related to velocity in that it acts to reduce velocity. In other words it causes moving objects to decelerate.
The friction force may also act as one of the forces in a moment that is causing motion. If the motion is rotary, or following any path, then the friction force may be simply a part of the system of forces that influences motion.
