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Friction. Don’t rub me the wrong way!. Kinds of friction. Static Exists between two surfaces that are NOT moving relative to each other Kinetic Exists between two surfaces that ARE moving relative to each other In MOST instances…. Static friction is greater than kinetic friction.
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Friction Don’t rub me the wrong way!
Kinds of friction • Static • Exists between two surfaces that are NOT moving relative to each other • Kinetic • Exists between two surfaces that ARE moving relative to each other • In MOST instances…. • Static friction is greater than kinetic friction
Proportional to the Normal Force • Ff= μs FN : Magnitude of frictional force due to static friction • Static Coefficient of Friction - μs • Ff= μkFN : Magnitude of frictional force due to kinetic friction • Kinetic Coefficient of Friction - μk μ – “mu” – small Greek letter M - symbol for coefficient of friction
Tribology • Contact Mechanicsof Moving Interfaces • Generally involves energy dissipation • Also encompasses the science fields of: • Adhesion • Friction • Lubrication • Wear
Friction Theory • Surface imperfections • Inter-particle attractions • Other?