### resistance | friction:

Air friction
* gets rapidly larger as speed increases.
* is affected by the surface roughness of the object.
* makes a leaf travel along in the wind.

Dynamic friction
* is almost always dependent on the relative sliding velocity
  - the friction between two objects that are moving relative to each other
* occurs between objects that slide across each other.

Fluid friction
* Some fluid friction involves fluid.
* is observed in the flow of liquids and gases.
* occurs when an object moves across or through a fluid.
* offers resistance.

Kinetic friction
* Some kinetic friction acts on trucks
  - refers to forces
* converts energy
  - kinetic energy

### resistance | friction:

Static friction
* acts between surfaces at rest with respect to each other
  - in the direction needed to prevent slipping
* applies to friction between surfaces when the object is at rest.
* force that resists motion.
* is greater than kinetic friction
  - normally larger than moving friction
* is the force required to make an object at rest begin to move
  - that acts to oppose sliding motion when objects are at rest
  - friction produced when the object is at rest
  - maximum force acting against any start of sliding
  - value of the limiting friction just before slipping occurs
  - what keeps a box on an incline from sliding to the bottom
  - when the friction is strong enough to stop movement between two objects
+ Friction: Force
  * The energy lost to friction is turned into sound and heat. Two kinds of friction are static and kinetic. Static friction is when the friction is strong enough to stop movement between two objects. Kinetic friction is when the frictional force is not strong enough to stop all motion.

### resistance | friction:

Traction
* Headaches Occur if painful sensitive parts of the head are moved, stretched, or displaced.
* alleviates pressure on the nerves as they leave the spinal cord.
* can reduce cervical dislocations, decreasing pressure on the cord.
* involves putting the bone under tension with the use of weights and pulleys.
* is also important for outdoor enjoyment and recreation
  - effected by the tire's inflation and plays a vital role in safety
  - friction between the tires and the road
* is important in caving boots for grip in deep mud or slippery cave passages
  - to movement and braking
* is the application of a force to stretch certain parts of the body in a specific direction
  - movement of particles by rolling, sliding, and shuffling along the eroded surface
  - resistance or friction happening between each tire and the ground surface
  - used to regain alignment of a fracture by applying force to the body part
* method of treatment that holds bones in position by using weights and pulleys.
* vectorial force constituted by intensity, direction and orientation.
* works in a gradual and natural way to increase the size of the penis.

### resistance | friction | traction:

Traction control
* prevent a vehicle's wheels from spinning by limiting power to the spinning tire.
* uses electronic monitors and controls to cut down on wheelspin.

Heat resistance
* is normally an inherent property of the fiber used in the manufacturing ropes.
* protects the resin from exposure to excessive temperatures.

Herbicide resistance
* increases chemical use in agriculture.
* is mobile since it spreads by both pollen and seed
  - now a major problem for cropping systems throughout Australia
* poses a threat to crop production in many countries.

Insect resistance
* is also a priority in the development of new germplasm.
* win-win both in small and large scale farming in the developing world.

Insulin resistance
* Some insulin resistance occurs at same time
* Some insulin resistance produces acid urine

Internal resistance
* has effects.
* increases with age and also as the battery's energy is used up.