How does the wings provide the lift to the aeroplane?
A wing creates lift by imparting a downward momentum to the air flowing above and below it. The rate of change of momentum is equal to Force (Newton's 2nd law), and therefore a reaction force pushes the wing up, producing lift (Newton's 3rd law).
The imparting of this downward momentum ("downwash") to the air results from an air pressure differential above/below the wing. If you know the pressure above the wing and the pressure below the wing, and the wing area, you can calculate the lift force on the wing since Force = Pressure x Area. If you don't know the pressures, you can get a rough estimate if you know what the average air velocities are above and below the wing. A wing creating lift will have higher speed air flowing over the top of it than flowing below it. By employing Bernoulli's Principle, you can calculate a pressure difference corresponding to the difference in velocity.
An airfoil shape is effective in generating lift since it helps to keep the air flowing smoothly around the wing, making the wing more effective in diverting the air downwards. Air tends to flow more smoothly around curved shapes rather than abrupt sharp edges which is why the top of an aircraft wing always is curved. Even a perfectly flat wing can create lift (such as in a toy balsa wood glider). However a flat wing isn't practical for a full sized airplane since it's not quite as effective in producing lift. The air doesn't flow smoothly past the sharp leading edge, resulting in a lot of drag and an abrupt stall.
Note that there is no requirement that the air molecules separating at the leading edge and flowing below the wing meet up with the same molecules that flow over the top. This is called the "equal transit time theory" and is a popular science myth that unfortunately has found it's way into flight manuals and even some undergraduate texts. However, aerodynamics engineers have known ever since they started doing wind tunnel testing that the air flowing over a lifting wing reaches the trailing edge sooner than the air below it. This is true even for a perfectly flat wing. This can be explained in terms of the circulation theory, which is an advanced concept.
I am going to assume that aeroplane=airplane when I answer this. An airplane stays in the air by generating lift on its wings. As long as an airplane can generate sufficent lift it can stay in the air. However once the lift being generated falls below what is required for the plane to stay up... uh oh.
While airplanes need to be in motion with enough momentum to create enough airspeed for lift off, helicopters can lift off vertically without any momentum of the aircraft. Both aircrafts need a rotary wing. Helicopter wings are rotary and have the capabilities to change the angle or pitch in order to create more or less lift. Airplanes have rotary and fixed wings.
An aeroplane with two sets of wings is referred to as a biplane. The original aeroplanes were biplanes. Wood and cloth were the primary materials used in building early planes because they are lightweight materials. However, these materials were not strong enough to allow for a long wing that could provide the necessary lift while supporting its own weight. To counteract this two wings were built and cables run between them to make the two…
The lift of the paper airplane is created by the wings and the thirst that you provide with your arm. Gravity is the force that brings the plane down and keeps it moving once the energy you provided with your arm has dissipated. The downward motion of the airplane caused by gravity keeps it moving forward which allows the wings to continue to provide lift.
They must have sufficient thrust from their engines and lift from their wings to overcome their weight and the aerodynamic drag forces. Most rockets do not have sufficient wings to lift them but their engines provide a thrust force that is greater than their weight and it keeps pushing them vertically in the air.
Yes, paper planes need wings to fly, if they were to be accurate to a real plane, since real planes have wings, so paper planes need wings, too. The wings provide lift for the paper plane, causing it to fly when thrown properly. No wings means it is just an ordinary folded piece of paper that you are trying to throw.