The principal of flight is that air travels faster over the longer surface of the top of a wing than it does underneath, causing reduced pressure on top, allowing the wing to lift. So what happens when a plane travels upside down?
208034
HI MAWBY --\n\nI ANSWERED THIS YESTERDAY IN SOME DETAIL.\n\nPLEASE GO TO THE SITE AND QUESTION BELOW.\n\nITS IN THE AILERONS, TABS, AND ELEVATORS.
590389
Well, A plane's speed is way too low to leave Earth's atmosphere.  For something to orbit around the Earth, it would have to move at speeds of at least 40000 km/h or MACH 40, the fastest airplanes have only went at MACH 4.  Now a plane can fly because it uses the atmosphere to lift it up.  But once it gets higher and higher, the atmosphere becomes too light to lift the plane up so there will be a certain altitude when the altitude levels off and the plane will no longer climb.
291835
This is about conservation of momentum. Any object on a rotating (and for our experiment atmosphere-less) planet has the same rotational momentum and angular velocity  as the surface. If it jups up, it will increase the radius, and therefore reduce the angular velocity, so it will land further behind.
332057
Cars are aerodynamic to reduce wind resistance but this does not create the Bernoulli effect necessarily.\n\nIn fact cars, especially race cars, are designed like upside down aircraft.  Instead of lift, they use the Bernoulli principle to create a down force.\n\nIf cars were round on the bottom and flat on the top then the Bernoulli principle would kick in and create lift.  Probably not enough lift to make the car fly but probably enough lift to make it uncontrollable on the ground.
372148
The earth is round and its gravitational pull draws us to its center.  Upside-down is really just pointing away from the core...from anywhere.
102586
If it's velocity is constant, and you jump straight up, you will land in the same place on the boat, because you, being on it, are travelling at the same velocity, and your horizontal velocity remains constant while you are airborne. (If you think you'll land in the water, then tell me, why is it that when you jump, on an airplane, you don't slam against the back wall?) Of course, you may have a difficult time maintaining your balance when you land, and that may cause you to fall into the water.
20028
Your question is too wide to be answered easily in one sitting.  So I'll look at how and why of aerodynamics (simply) and then answer the speed bit.\n\nThis a bit of material I wrote for flight cabin staff to help them understand these principles.\n\nLift is the aerodynamic force that counteracts gravity and holds an airplane in the air. Most of the lift required by an airplane is created by its wings, but a certain portion is also generated by other parts of the aircraft, such as the fuselage. But what actually causes the lift to be created?\nAir is a fluid, just like water. Lift can only be generated when a fluid is in motion. For example, a wing must be passing through the air or the air must be moving around a stationary wing, one or the other. (The way it usually happens is that the wing is doing most of the moving, although the air may be moving, at the same time.)  The wing is moved through the air by the thrust generated by the aircraft’s engines.\n\nMost aircraft wings have a special, basic shape as viewed edge-on: The upper surfaces are curved and their lower surfaces are flatter. This shape is what works with the fluid motion of the air to create lift. As air moves around a wing, some goes over the top and some goes underneath. The air that goes over the curved upper surface undergoes two important changes: it is reduced in pressure and it is accelerated downward (as it leaves the trailing edge of the wing). The wing is forced up into the region of reduced air pressure above the upper surface of the wing by the higher air pressure beneath the wing. Also, the downward acceleration of the air (downwash) at the trailing edge forces the wing upward.\n\nSo this is the basis of aerodynamics.  Roraty wing aircraft (helicopters) work on the same basis, the aerofoil is rotated and lift created by the rotors (moving aerofoils). The thrust to move the aircraft forward is produced by tilting the rotor head, in the direction required.  Hence it can move forwards, sideways and backwards.  But the explanation would take a separate large answer.\n\nAs for speed, the maximum forward speed of the aircraft is determined by the thrust available, but the aircraft is limited by the design of the wing, the wing shape for a low speed high lift glider is very different to that of a supersonic aircraft.  The lowest speed is really controlled by the wing.  As the aircraft sppeed reduces so does the speed of the flow over the wing, surface friction slows it down further until the air refuses to flow over the aerofoil and it breaks up into turbulence and all lift is lost.  A number of things can be done to get this point at which the lift is lost (stall) at the lowest speed possible - such as flaps, slats etc (but this is another long answer).  On helicopters there is no slowest speed as the aircraft will just hover when it stops moving forward, but its maximum forward sppeed is limited by the air over the blades going sonic and loosing lift, and problems with the trailing blade (the one that is heading towards the back of the helicopter in forward flight.) Again another long answer.\n\nHope that helps.  The book below is the RAF's bible on aerodynamics.
299827
As a skydiver falls (caused by gravity), he encounters the force of air resistance. The amount of air resistance is dependent upon two variables:\n\n1.  the speed of the skydiver\nAs a skydiver falls, he accelerates downwards, gaining speed with each second. The increase in speed is accompanied by an increase in air resistance. This force of air resistance counters the force of gravity. As the skydiver falls faster and faster, the amount of air resistance increases more and more until it approaches the magnitude of the force of gravity. Once the force of air resistance is as large as the force of gravity, a balance of forces is attained and the skydiver no longer accelerates. The skydiver is said to have reached a terminal velocity.\n\n2.  the cross-sectional area of the skydiver. \nA skydiver in the spread eagle position encounters more air resistance than a skydiver who assumes the tuck position or who falls feet (or head) first. The greater cross-sectional area of a skydiver in the spread eagle position leads to a greater air resistance and a tendency to reach a slower terminal velocity. The importance of cross-sectional area to skydiving is also demonstrated by the use of a parachute. An open parachute increases the cross-sectional area of the falling skydiver and thus increases the amount of air resistance which he encounters (as observed in the animation below). Once the parachute is opened, the air resistance overwhelms the downward force of gravity. The net force and the acceleration on the falling skydiver is upward. An upward net force on a downward falling object would cause that the object to slow down. The skydiver thus slows down. As the speed decreases, the amount of air resistance also decreases until once more the skydiver reaches a terminal velocity.
146010
An aircraft has 2 methods of turning. One is yaw, in which the rudder on the tail simply moves from side to side, causing excess drag on one side and hence turns the plane. Greater turning is achieved by first rolling the plane along its axis and then pitching upward the nose upward, which is now actually sideways.
669834
In order to create lift, the upper surface of a wing must be longer than the lower surface. That's why wings are curved. The bottom is flat and the top is curved. The F-117 doesn't have a "curve", but the upper surface is shaped with flat plates so that the upper surface is longer than the lower surface. It's not as aeordynamic and efficient as a nice, smooth curve, but I'll take not being seen over efficiency any day in a war.
20645
I have to assume that you're familiar with general aerodynamics. If not, there's really not enough space to answer your question here.\n\nThe biggest physics differences between a helicopter and an airplane are torque, translational lift, and retreating blade stall.\n\nA helicopter's fuselage will tend to turn opposite the direction of the rotor, particularly at a hover or a slow speed. (Some streamlining occurs in flight.) The "tail rotor" is actually called an "anti-torque rotor" because its installation is designed to counteract the main rotor's torque. (Notice that twin rotor helicopters don't have anti-torque rotors because the main rotors rotate in opposite directions and counteract each other's torque.)\n\nNext is effective translational lift. At a hover and at slow speeds, generally below 30 KIAS, a helicopter is flying in its own rotor wash. A lot more lift and constant control inputs are required to maintain steady flight. Lift in a helicopter is created by the rotating blades and is increased (or decreased) by raising the collective (a “joystick by the pilot’s left leg) which increases (or decreases) the rotor’s angle of attack. Note: During all of this, the rotor maintains a constant R.P.M….it does not spin faster when climbing and slow down when descending.\n\nAlso, some of this lift is used for thrust to move the helicopter forward, or sideways, or backward. This is why you see a helicopter nose down when it’s taking off. The rotor is the “wing and the propeller” at the same time.\n\nFinally, retreating blade stall limits the speed of a helicopter. Sitting on the ground and in a still wind at operating R.P.M. the wind is blowing over the blades at a steady speed. (Of course the blade root’s speed is much lower than the blade’s tip because it has less far to travel.) But in forward flight at, say 100 KIAS, the advancing blade has an extra 100 knots relative wind added to its speed. The retreating blade, going opposite to the relative wind is LOSING 100 knots relative wind. The faster you go, the more the retreating blade loses lift and eventually stalls; that is loses lift completely and the helicopter will roll over.\n\nThis is about all I can tell you in a short time, but it’s all very interesting and surprisingly inefficient. I’ve attached some links that will go into more detail. Hope this helps!
569338
Condensation. As the air moves over the wings of the plane, the moisture in the air collects on the wing. It is pulled to the wingtips where it then is blown off, and condenses into small lines of "cloud"
171717
as far as the airplanes are concerned the bernouli (probably spelled wrong) principle was the accepted belief for a long time but has recently been disproven as the primary reason.  Bernouli's principle was the high pressure under the wing and low pressure atop creating lift. \nThe new theory is something to do with the air flowing over the wing sticks to it due to a vaccum created on the surface by moving air. the air then shoots downward off the back of the wing causing the wing to react upward kinda like a jet engine. That was my very loose understanding of it. apparently a barn door creates as much lift as an airofoil teardrop shapped wing.
291020
upside down\nwhile driving
439141
1) Billy Boy's answer is exactly not the right answer. It is a common misconception that lift is generated due to the rounded "airfoil" shape, forcing fluid to travel faster on top, and thus generating a pressure gradient through incompressible Bernoulli's equation. That is INCORRECT. A flat board can generate lift if you tilt it and swing it through the air.\n\n2) I don't think you really want a mathematical explanation. Because the mathematical explanation involves complex partial differential equations, or, if you prefer, integral equations. These are known as the Navier-Stokes equations, and they govern 3D fluid flow. A fully mathematical answer would be: the wings generate lift because the solution to the Navier-Stokes equations around the wings shows an upward momentum deficit in the flow, thus generating lift on the wings.\n\n3) But really, it's quite simple. When the plane is flying, the wing is pushing air down. Not straight down, but slightly down, and by Newton's 3rd law, the wing is pushed up. (Who's doing the work? The engines are pushing the plane forward, which forces the wings to push air down.)\n\nIn fact, if you actually follow the link Billy Boy gave, NASA would tell you the same - in different and probably more confusing terms.
306260
Because the top side and bottom side of wings are shaped differently, air travels at different rates over the surfaces, causing lift.  The answer is C.
65703
As the heat of the sun--or anything else--causes air to rise, its radius of rotation changes; this change in radius would cause a change in the angular momentum, so to conserve the angular momentum of the particle, the rising air mass has to develop a small additional velocity (it turns out to be opposite the rotation of the earth) as rises.  Here, in the northern hemisphere, that air flow would go north and east.  Also, as the air moves north, the angular momentum changes--aggravating that easterly vector in the velocity.  Eventually, the air cools, and going down & back south causes more changes; oddly, and I can't recall the precise physics here, it still retains a major easterly vector.  Thus, because of the earth's spin, a particle of air that rises and falls in one of the large convection bands (living between the jet streams) will do a spiral--think a widely stretched spring, here.