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FRICTION

A FORCE

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FRICTION

A FORCE

1.Even smooth surfaces are rough and jagged at the microscopic level.

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FRICTION

A FORCE

2.These jagged surfaces tend to lock together. This makes it harder for things to slide past each other. This is friction.

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FRICTION

A FORCE

3.Two things influence the amount of friction: Roughness and Weight.�

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FRICTION

A FORCE

4.The rougher a surface, the greater the friction. The less rough (smoother) the surface, the less the friction.

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FRICTION

A FORCE

5.The greater the weight of something, the greater the friction. The lighter something is, the less friction there is.

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WINTER

Template

4 Classes of Friction

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WINTER

Template

01

4 Classes of Friction

There are 4 classes of friction: static, sliding, rolling, and fluid.

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02

Static (not moving) friction: Friction between 2 objects BEFORE one starts to move. This is slightly greater than sliding friction.

4 Classes of Friction

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03

Sliding friction: Friction between 2 objects as they slide past each other. This is slightly less than static friction.

4 Classes of Friction

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04

4 Classes of Friction

Rolling friction: As something moves on wheels, rolling friction keeps the wheels from sliding around.

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05

4 Classes of Friction

Fluid friction: The friction between a solid and a fluid. This is the least of all frictions. e.g. stepping from wet floor to dry floor, you may slip and fall.

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Air Resistance

Friction from the Air

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Air Resistance

  • Air resistance is a special case of fluid friction in which air acts like a very thin fluid.

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Air Resistance

  • We don't normally notice air resistance...air particles flow around us easily.

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Air Resistance

  • As you go faster and faster, air particles start to bunch up in front of you as more and more try to move around you.

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Air Resistance

  • As air particles bunch up, it becomes harder to push through them...air resistance.

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Air Resistance

  • Terminal velocity is when an object's weight (the force it feels from the Earth) is balanced by air resistance.

*Remember….when forces become� balanced there is no acceleration

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Air Resistance

Friction from the Air

FIN