Kinetic friction resists relative sliding between contacting surfaces.
Difficulty
Beginner
Read time
5 min
Prerequisites
Basic algebra and consistent SI units
Source
OpenStax, College Physics 2e, §5.1 (Paul Peter Urone and Roger Hinrichs)Textbook reference retained from the OpenFormulaGraph dataset; adaptation credits and license are provided below.
Adapted from OpenFormulaGraph, under CC BY 4.0.
FormuLab adapted the notation, explanations, assumptions, and topic placement, and expanded the numerical check into a worked example.
Kinetic friction resists relative sliding between contacting surfaces. The dry-friction model estimates its magnitude from the normal force and the kinetic coefficient, with the direction opposing local sliding.
| Symbol | Meaning | Units |
|---|---|---|
| Sliding friction magnitude | ||
| Kinetic friction coefficient | ||
| Normal contact-force magnitude |
Estimate resistance when a load slides.
Supply the friction term in a work calculation.
A sliding contact has a normal force of 20.0 N and kinetic friction coefficient 0.300. Find the friction magnitude.
Textbook reference retained from the OpenFormulaGraph dataset; adaptation credits and license are provided below.
Adapted from OpenFormulaGraph, under CC BY 4.0.
FormuLab adapted the notation, explanations, assumptions, and topic placement, and expanded the numerical check into a worked example.
Assumptions
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