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Friction. Friction Notes. Force that resists change in motion Symbol: F ric or F f Coefficient of Friction symbol: µ = F ric / F N no units. Types:. Static Friction: Friction btwn . stationary surfaces Kinetic Friction: Friction btwn . moving surfaces. Friction Facts.
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Friction Notes • Force that resists change in motion • Symbol: Fric or Ff • Coefficient of Friction • symbol: µ = Fric/ FN • no units
Types: • Static Friction: Friction btwn. stationary surfaces • Kinetic Friction: Friction btwn. moving surfaces
Friction Facts • Acts in the opposite direction of the moving object • Parallel to the surface of contact • Caused by electrostatic force btwn. outer electrons of materials • Static ≥ kinetic • Dependent on kinds of materials used • Independent of surface area and speed
Equation • Fric = µFN • can only use this equation if FN is perpendicular to the surface
Drag and Terminal Velocity • Drag (air resistance) = friction of objects that move through the air • Terminal velocity = constant velocity achieved when friction is balanced by Fg