Which mechanisam used to stop the aeroplane?
469801
When an airplane lands, the thrust from the engines is diverted forward to slow the plane down.  Then when the plane has slowed to a certain speed, brakes are applied.
581524
Plane Train Automobile ship
396452
1. reduce the force at which the surfaces press together.\n2. allow one surface to slide on top of a film of air rather than the other surface(a la hovercrafts and air hockey)\n3. reduce the roughness of the surface by polishing or using lube.\n\n***I know... they're more than one way... lol***
138273
The airplane prop works just like the prop in a outboard motor in a boat. The prop has blades which have a pitch on them (angle) which in trun "paddles" through the air - the air is pulled over the blades and in turn pulls the motor through the air. (which of course, is attached to the wing which creates the lift required to get the plane off the ground)\n\nThe boat prop is a great example to use because you can see the water and how it flows over the blades.
1122282
The vacuum brake is a braking system used on trains. It was invented in 1877 in the USA, where it enjoyed only a brief period of popularity, primarily on narrow gauge railroads. The system took a greater hold in the United Kingdom, being used there as the primary form of train braking until the 1970s. Vacuum braking is for all practical purposes now a dead technology; it is not in large-scale use anywhere in the world, supplanted in the main by air brakes.\n\nVacuum brakes permit the automatic application of brakes down the length of a train from a simple control in the driver's hand. They are also fail safe, since they default to an applied state using atmospheric pressure; power in the form of vacuum is used to release the brakes, so if vacuum is lost due to malfunction or the train breaking apart, the brakes are automatically applied.\nVacuum brakes have now been largely superseded by air brakes which work on a similar principle but use compressed air instead of a vacuum. This allows for more braking power, since the pressure differential between atmospheric pressure and a feasible vacuum is less than that between atmospheric pressure and a realistic brake-pipe pressure.\nEach vehicle is fitted with at least one brake cylinder. These are of large diameter, as only the force from atmospheric pressure is used to apply the brakes (see below). They are enclosed in an airtight case (with a gland for the piston rod) and are mounted vertically with the piston rod beneath. Connection to the brakes is by brake rigging. The brakes themselves take the form of cast iron (or, rarely, wooden) blocks which are pivoted to bear on the train wheels.\n\nIn sequence, the method of operation is: On coupling up the locomotive, air is exhausted from a pipe running the length of the train by a large steam-operated ejector ("making a brake" – UK). Each cylinder is arranged so that this vacuum initially acts equally on both sides of the brake piston. The piston, which is of cast iron, drops under gravity and releases the brakes. The large ejector is then turned off to save steam and a small ejector (or light pump worked from the crosshead) is employed to maintain the vacuum.\n\nIf air is admitted to the train pipe, either under the control of the driver or because of an equipment failure, a one-way ball valve at each brake cylinder (or sometimes a one-way piston sealing ring, as found in a bicycle pump) prevents it from entering the upper part of the cylinder. The pressure differential (effectively, the air at atmospheric pressure entering the train pipe) closes the valve and forces the piston upwards, thus applying the brake. The airtight case, which is open to the upper chamber, is acting as a “vacuum reservoir” for the upper part of the cylinder, ensuring fail-safe operation.\n\nTo release the brake the driver's brake valve is closed and the vacuum restored by either the small or large ejector, as necessary.\n\nTo discharge the vacuum under fine control the driver is provided with a graduable brake valve (which usually also incorporates the controls to admit steam to the ejectors) and a vacuum gauge. The running “pressure” is usually in the range of twenty-one to twenty-five inches of mercury (a perfect vacuum is regarded as thirty-one inches of mercury). During braking the driver will watch the gauge to estimate how firmly he/she is applying the brakes – a light application sees the vacuum drop to about fifteen inches and a heavy one to about ten. Of course in an emergency application ("dropping the handle" – UK) the train pipe vacuum can be completely destroyed. During all normal braking, anticipation and careful attention to the pressure is required as, even with the large ejector turned on, it takes some time to restore the vacuum, release the brakes and allow the train to proceed. It is good practice to restore the vacuum slowly when the train is in motion, to avoid releasing the brakes at the front
149882
A craft is built on a solid platform, preferable strong but light weight.  The platform has a flexible skirt creating a border around the platform.  A very high powered fan forces air into the empty space between the platform and the ground, which is contained by the skirt.  As the flow rate of air increases, so does the pressure under the platform.  The pressure difference between the interior cavity and the top of the platform creates lift, just like an airplane wing.  As it lifts up, a gap forms between the ground and the skirt.  This reduces the pressure and lowers the lift.  The gap makes a self-regulating system.  As the gap shrinks, the pressure increases.  As the gap gets larger, the pressure decreases.  In this way the hover craft has a regulated height above air OR water.  Hovercraft over water can use higher power fans to elevate them so the craft won't impact waves as easily.  The air gap is higher, and the flexible skirts can interact with the waves and keep lift under the craft at all times.\n\nSimple hovercraft for the home builder can be made out of plywood, using a lawnmower engine for the lift fan, and another enging for the pushing fan.  Commercially available units can have one motor for both purposes and are a blast to drive.
416972
As the plane's engines provide thrust, there is a certain amount of force countering it in the form of drag.  So if the thrust from the engines were to drop off, the drag force would be greater than the forward force.  (Eventually, the drag force will also be reduced so that the two opposing forces will be in balance again.)  Because of this, the plane will immediately start to decelerate.
552666
For a simple answer look up how a plane propeller works.
847392
Start from http://www.aero.org/programs/control.html
761342
We did something like this in my physics lab with an Atwood machine.  It was a pully with weights hanging from it.  I can't exactly remember how it worked, but maybe this will inspire you.  We also did something with an air track and these two masses colliding and we'd see which one would go in which diretcion.  You need a nearly frictionless surface, like an air hockey table or ice slab.
1160918
Popular Mechanics Article here:\nhttp://www.popularmechanics.com/science/defense/1227842.html\nPentagon Site here:\nhttp://www.abovetopsecret.com/pages/911_pentagon_757_plane_evidence.html\nStructural failure report by NIST here:\nhttp://wtc.nist.gov/\n\nA little common sense will get you thinking the right way.  Good luck.
942353
ERNEST FREDERICK HUBER \n\nvisit this web for more information\n\nwww.modelaircraft.org/museum/bio/Huber.pdf
670144
Usually magnets or wedges that are pressed down inbetween two metal rails:\n\n&#92;/\n||\n\nSorry that i couldn't draw well via the keyboard, but imagine the above as a cross section of the wedge, and the lower vertical lines as a cross section of the metal or semi-metal rails...the rails can taper outward a little to create more surface-to-surface contact.  you can imagine the normal force exerted onto one another between the wedge and the rails as the wedge is pushed into the rails, this normal force grows fast quickly as more force is exerted onto the wedge.  and i'm assuming that you're taking or have taken physics courses, so you should know that let's say a box sliding on the floor, has a frictional force of kw, where k is the kinetic friction constant, and w is the weight of the box, for the wedge/rail setup, we would replace w with the normal force, and the equation wouldn't be that simple, in fact, the force would grow almost exponentially as more force is exerted downward on the wedge since the wedge gets wider and wider.  think of it as a brake/rotor setup on a car, but instead of circular, it's linear, and instead of the brake pads squeezing on the rotor, it's the rotor being pushed into the pads.  this similar setup is used on trolley cars, which is why on some trolley trails, you see another pair of rails, situated close together, inbetween the two main rails for the wheels.\n\nnow in an emergency, there is no stopping anywhere else on the roller coaster track except on the boarding/exiting platform.  the engineers made it so that the momentum of the cars will take them through the entire track system no matter what the (realistic) load distribution is.  can you imagine trying to stop an extremely fast set of attached cars on a track with twists, turns, and loops?  and on top of that, the decision when and where to stop the cars is left to some teenage kid in the booth?  very unsafe and unreliable.
522890
Yes this happens and it happens because when an airplane lands it displaces air around it with a high pressure and speed.This large volume of displaced air with high speed exerts a high pressure on the car and it flies away from the track
192605
Only after touchdown, not when the aircraft is in flight.  These are usually governed by squat switches on the landing gear to assure they do not deploy in flight.  The throttles are engineered to require the pilot to reduce the power setting before he can deploy the reversers, then he can reapply power with the reversers out.\n\nYes this reduces brake wear, plus adds to the stopping force available.
1158529
The "black box" is actually bright orange, so it can be found easily.  It's made of quarter inch thick stainless steel, while the skin of a plane is made of aluminum about 28/1000 of an inch thick.  If the plane were built of materials even 1/10 the strength of the black box, it could never get off the ground.\n\nEven if you could make a plane out of concrete and steel I-beams, and somehow get it to fly, if it hits the ground at 100mph, it's going to get crunched, no matter how strong it is.  That energy has to go *somewhere*, and a good portion of it will go into the plane's structure.
140612
Yep.  A fan will do the trick, or if it's a vehicle used for a specific purpose (like carrying something from set point A to set point B) a pulley system would work.  I don't know the exact equations involved, but the fan's windpower strength should be (obviously) greater than the mass of the vehicle, and should have some kind of failsafe cutoff switch as well as a means to decrease power to the fan, for (again, obviously) safety reasons.