Kinetic friction
Also: sliding friction
Friction acting between surfaces that slide relative to each other.
A simple Coulomb model uses magnitude μ_kN opposite sliding, though real friction varies with material, speed, temperature, and lubrication.
- Formula
F_k ≈ μ_kN
Example A skidding wheel experiences sliding rather than static contact friction.
Common misconception Kinetic friction is not universally constant or always lower in every material system.