Friction

## Contents

* 1 What is friction?
* 2 What does the force of friction depend on?
* 2.1 Static Friction :
* 2.2 Kinetic Friction
* 2.3 Sliding Friction
* 2.4 Rolling Friction
* 2.5 Fluid Friction
* 2.6 Air Resistance

### 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.