1. Friction Friction always opposes motion or the applied force (called a non-conservative force) Force due to the rubbing of two surfaces against each other Typically….. 0< μ < 1 0 would be “frictionless” and μ=1 is really “sticky”

3. 5.29 micrometer (μm) = 1/500 inch A magnified view of a frictionless coating

4. The road from static to kinetic friction

5. Friction (types) Kinetic Friction: this is moving friction Static friction: this is non-moving friction Static friction > sliding friction Both friction types are defined by the coefficient of friction, μ (either kinetic, μ k or static, μ s )

7. Fiction Equations