Brake

A brake is a mechanical device which prevents the movement. The rest of this section is devoted to different types of vehicle brakes.

Most often, the friction brakes used to convert kinetic energy into heat, though other methods of energy conversion may be employed. For example the braking energy recovery becomes much electrical energy which can be stored for later use. Other methods of conversion of kinetic energy into potential energy stored in forms such as compressed air or pressurized oil. Eddy current brake use magnetic fields to convert kinetic energy into electric current in the brake disc, drift, or rail, which is converted into heat. However, other methods of transformation of the kinetic energy of braking even in different ways, for example by transferring the energy to a rotating wheel.

The brakes are generally applied to the axes of rotation 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 two wheel brakes and drag flaps raised into the air during landing .

As the kinetic energy increases quadratically with velocity (K = mv ^ 2/2), an object moving at 10 m / s is 100 times more energy than one of the same mass moving at 1 m / s, and accordingly the theoretical distance brake when braking in the tensile strength is 100 times longer. In practice, fast vehicles usually have significant air drag, and energy lost to air resistance increases rapidly with speed.

Almost all wheeled vehicles with a brake of some sort. Even baggage carts and shopping carts may have to use in a moving ramp. Most aircraft are equipped with wheel brakes on the undercarriage. Some also had air brakes designed to reduce speed in flight. Notable examples include gliders and some World War II aircraft at the time, primarily some fighter aircraft and many dive bombers of the era. These allow the aircraft to maintain a safe speed on a steep slope. The dive bomber B 17 used Saab landing gear deployed as an air brake.

Friction brakes on automobiles store braking heat in the drum brake or disc brake while braking then conduct the air slowly. When traveling downhill some vehicles can use their engines to brake.

When the brake pedal of a modern vehicle with hydraulic brakes is pushed, ultimately a piston pushes the brake pad against the brake disc which slows the wheel down. In the drum brake is similar to the cylinder pushes the brake shoes against the drum, which also slows the wheel.