Friction Force Calculator
f = μ × N. Force resisting motion between contacting surfaces.
Result
Friction force (kinetic)
150.00 N
μ = 0.3 × N = 500 N.
- μ0.3
- Normal force500 N
- Friction150.0000 N
- Typekinetic
Step-by-step
- f = μ × N = 0.3 × 500 = 150.0000 N.
- Kinetic: friction during motion (typically μ_k < μ_s).
How to use this calculator
- Enter μ for the surfaces in contact.
- Enter normal force.
- Pick static or kinetic.
About this calculator
Friction force = coefficient × normal force. Coefficient depends on material pair: rubber on dry asphalt 0.7-0.9, rubber on wet asphalt 0.4-0.6, steel on steel 0.1-0.6, ice on ice 0.02-0.1. Static friction (μ_s) prevents starting motion; kinetic (μ_k) opposes ongoing motion. Almost always μ_s > μ_k — this is why a stuck box suddenly slides easily once it breaks free.
Frequently asked
Empirical — measured for material pairs. Hyperphysics, NIST tables, or engineering handbooks list standard values.
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