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What is friction?[edit | edit source]

Friction is a force, affects motion. Friction acts on materials in contact with another, or acts in different direction in opposite motion.

What does the force of friction depend on?[edit | edit source]

  • Nature of the materials.
  • How hard the surfaces are pressed together

..such as Rubber vs. Concrete, and not Steel vs. Steel (Rubber vs. Concrete > Steel vs. Steel)

Static Friction :[edit | edit source]

Friction between the surfaces in contact and which are relatively at rest.

  • Opposes movement of stationary object
  • Moving furniture
  • Hardest part getting moving
Kinetic Friction[edit | edit source]
  • Acts on objects in motion
  • Once object begins moving, less force to keep in motion
  • Sliding, Rolling, Fluid
Sliding Friction[edit | edit source]
Basketball shoes prevent slipping, relation to Sliding Friction
  • Two objects slide past one another
  • Basketball shoes prevent slipping
Rolling Friction[edit | edit source]
  • Objects such as wheel or ball rolls across surface
  • Easier to overcome than sliding friction
  • Rolling friction is always less than static friction, as the time period for contact of irregularities between the bodies is less in rolling friction compared to static friction.
Fluid Friction[edit | edit source]
Boy with a helmet, on training wheels, relation to Fluid Friction
  • Solid objects move through fluids
  • Cyclists use aerodynamic and spandex to reduce friction
  • Vehicles such as aeroplanes and cars have a special shape known as streamlined shape to reduce windshear or drag.
Air Resistance[edit | edit source]
  • Friction acting on something moving through air
  • Don't notice unless at high speed.