Editing Brake (section)

==Background==
{{More citations needed section|date=February 2016}}
Most brakes commonly use [[friction]] between two surfaces pressed together to convert the [[kinetic energy]] of the moving object into [[heat]], though other methods of energy conversion may be employed. For example, [[regenerative braking]] converts much of the energy to [[electrical energy]], which may be stored for later use. Other methods convert [[kinetic energy]] into [[potential energy]] in such stored forms as [[Compressed air energy storage|pressurized air]] or pressurized oil. [[Eddy current brakes]] use magnetic fields to convert kinetic energy into electric current in the brake disc, fin, or rail, which is converted into heat. Still other braking methods even transform [[kinetic energy]] into different forms, for example by transferring the energy to a rotating flywheel.

Brakes are generally applied to rotating axles or wheels, but may also take other forms such as the surface of a moving fluid (flaps deployed into water or air). Some vehicles use a combination of braking mechanisms, such as drag racing cars with both wheel brakes and a parachute, or airplanes with both wheel brakes and drag flaps raised into the air during landing.

Since kinetic energy increases [[quadratic function|quadratically]] with [[velocity]] (<math>K=mv^2/2</math>), an object moving at 10&nbsp;m/s has 100 times as much energy as one of the same mass moving at 1&nbsp;m/s, and consequently the theoretical [[braking distance]], when braking at the traction limit, is up to 100 times as long. In practice, fast vehicles usually have significant air drag, and energy lost to air drag rises quickly with speed.

Almost all [[wheel]]ed [[vehicle]]s have a brake of some sort. Even [[baggage cart]]s and [[shopping cart]]s may have them for use on a [[moving ramp]]. Most [[fixed-wing aircraft]] are fitted with [[Aircraft disc brake|wheel brakes]] on the [[Landing gear|undercarriage]]. Some aircraft also feature [[air brake (aircraft)|air brakes]] designed to reduce their speed in flight. Notable examples include [[Glider aircraft|glider]]s and some [[World War II]]-era aircraft, primarily some [[fighter aircraft]] and many [[dive bombers]] of the era. These allow the aircraft to maintain a safe speed in a steep descent. The [[Saab 17|Saab B 17]] [[dive bomber]] and [[Vought F4U Corsair]] fighter used the deployed undercarriage as an air brake.

Friction brakes on [[automobile]]s store braking heat in the [[drum brake]] or [[disc brake]] while braking then conduct it to the [[air]] gradually. When traveling downhill some vehicles can [[engine braking|use their engines to brake]].

When the brake [[Automobile pedal|pedal]] of a modern vehicle with [[hydraulic brake]]s is pushed against the [[master cylinder]], ultimately a [[piston]] pushes the [[brake pad]] against the [[Disc brake|brake disc]] which slows the wheel down. On the [[brake drum]] it is similar as the cylinder pushes the [[brake shoe]]s against the drum which also slows the wheel down.