Do planes fly or do they just accelerate so swiftly that they are constantly falling round the Earths curve?

Question

The Earth is a sphere. Imagine a toy plane on top a beach ball. If you push it fast enough it will come away from the curve of the beach ball. Now imagine the ball suspended in the air with gravity in the centre of it and the toy plane had a constant controlled force behind it, push the plane slowly and it will just travel round the ball always in contact with it but push it fast enough and it will travel around the ball at a distance away from its surface, is this the same as flying? Is flying really just controlled falling round the curve of the Earth?

Answer 1

depends on your definition of flying, which is commonly known as moving through the air using wings or an engine, but good question though. but IMO flying is controlled falling :), since if you look at the physics of it, you are constantly trying to counter gravity which is towards the center of the earth.

Answer 2

It definitely flies, and I'll give you two reasons:

1. If it were just falling around the Earth, everyone inside would feel weightless, because that is exactly what an orbiting satellite or shuttle does. And, if a plane were to be able to fall around the earth, at it's altitude, it would have to be traveling at a tremendous amount of speed. It would destroy the plane.

2. The plane utilizes lift, which is due to Bernoulli's principle. Besides, the plane has to get into the air somehow, which is from the lift.

The lift comes from the design of the wing. The wing is shaped such that the air moving over the top is going much faster than the air moving under the bottom. Moving fluid creates a low pressure, so there is lower pressure at the top of the wing compared to the bottom. As a result, there is a net force pushing up on the wing which is called lift.

Once the plane reaches the critical speed where the lift equals the weight, it is able to take off. The speed depends on the weight of the plane and the area of the wing span.

Answer 3

Planes do actually fly. The Earth no matter how round has a distance from one drop to the other. Over that distance there is a very slight angle. So the plane would need to be lifted under its own power to take off.

When the plane is in air it is kept there by the air generating lift under the wing. It is propelled by the turbines or jet engines. When it is time to land speed is reduced lift loses its hold more and more. then the plan makes it's safe touch down (hopefully).

Answer 4

They actually fly. There is a pressure difference between under the wing (high pressure) and above the wing (low pressure) creating lift.

Think of a remote control airplane. You can certainly drive a car faster than they fly, but the car does not leave the ground.

Also, if planes did not actually fly, but only speed, then they wouldn't need wings. (I assume you meant speed as opposed to "acceleration" in your question. Planes can fly at constant velocity, with no acceleration at all.)

Also, if planes were simply a controlled fall, there would be no way to explain the way a plane is able to turn. Most planes do not have the ability to change the direction of force supplied by the propeller (or jet engine or whatever).

Answer 5

The scale separation between flying, and orbit is quite large. Flying simply forces fluid to accelerate in a differential manner resulting in a pressure imbalance, which 'pushes' the wings up. Orbit is when you have accelerated to a sufficient velocity at your radius from a gravitational source that the centripetal acceleration balances gravitational acceleration. That velocity for near surface orbit would be ~ 7600 m/s, but you would be toasted by friction far before reaching that. A typical 50 cal bullet reaches 900 m/s to give you an idea of the problem.

Answer 6

We are familiar with cars, trains and other vehicles moving on ground.

Actually there is no difference between cars on roads and planes flying in atmosphere. Ships float in water. Planes float in air; the difference between ships and planes is that ships float on the top surface of water whereas planes float, not on the surface of air but on the surface of air at a particular height.

First we shall see the motion of cars on the road. The weight of car is balanced by the earth’s normal reaction (up thrust, or upward force). If there is no ground on its path the car is pulled toward of the earth. That is the car traces the ups and downs of the road.
A car going in high speed can cross a narrow river having no bridge if the approaching road is inclined upward. If the road is horizontal, the car will definitely fall into the river. Thus one can understand the car is always pulled down ward by the earth.
We know that the gravitational pull is 10m/s^2. But when the car is speeding up, the weight (the down ward push) is reduced a little. If a car can go with a speed of 8 km/s (28800km/ hour), then it can ‘fly’ on the surface of ground. That is it weight becomes zero. It will not press the earth surface. It will revolve the earth. (Of course we have to take into account the spinning of earth).

If a ship can move with such a speed, then it will not touch the sea water, it will just ‘fly’ on the surface of water. It will not push the water down ward.

If a car or ship exceeds this speed, then they will be lifted up from the surface of earth and will revolve round the earth in a higher orbit.

Compared to the earth’s radius the height in which planes fly is small; therefore, we can say that planes will go round the earth with out giving any downward pressure on the air column, only when they move with a speed of 8 km/s.

The actual flight of plane is that they are moving in an air column of certain height.

Just like the ground is giving up thrust to cars, or water is giving up thrust to ships, air column is giving up thrust to planes

A car traces the ups and downs of a road; a plane traces the ups and downs of pressure of air column.

Answer 7

A normal plane or aircraft cannot achieve "escape velocity". Only rockets have enough sustained thrust to get that fast. And, you are right in the sense that nothing in orbit around the earth is in zero g. Everything in orbit is free-falling around the planet and still experiences what is referred to as micro-gravity.
When something flies through the air, the air flow causes various pressures in various places and control surfaces on the aircraft are used to maneuver the aircraft. Since there is no air in space, thrusters are used to orientate and move a spacecraft.

Answer 8

A plane "flys" since it stays in the air using lift created by the aerodymanics of the wing. For what your explainig, the object has to be travaling at the escape velocity of the given planet. Quote from wikipedia.org "On the surface of the Earth the escape velocity is about 11.2 kilometres per second. However, at 9000 km altitude in "space", it is slightly less than 7.1 km/s."

Answer 9

no, they are flying. The pressure on the bottom of the wing is greater than the pressure on the top of the wing because of the speed of the air moving around the specially shaped wing. This causes the wing, and the plane, to lift.

That's why Cessnas are tied down at airports, because strong winds can cause them to lift because they are relatively light planes.

Answer 10

The constantly falling idea is called orbitting. Orbitting is only practical above the atmosphere. Like the other posters said, flying is using the air to keep the plane up.