|
>>
|
No. 73065
File
143374802795.jpg
- (491.10KB
, 1024x1436
, 10e35a510de09479820786a92e7231e0.jpg
)
>>73062
This post is pretty stupid bro.
>Planes, whether they be piston or jets, don't need the movement, though, just the air intake to push the plane forward.
Let's start with some very basic definitions here: (From Wikipedia):
>Lift: A fluid flowing past the surface of a body exerts a force on it. Lift is the component of this force that is perpendicular to the oncoming flow direction.[1] It contrasts with the drag force, which is the component of the surface force parallel to the flow direction. If the fluid is air, the force is called an aerodynamic force. In water, it is called a hydrodynamic force.
>Momentum: In classical mechanics, linear momentum or translational momentum (pl. momenta; SI unit kg m/s, or equivalently, N s) is the product of the mass and velocity of an object. For example, a heavy truck moving rapidly has a large momentum—it takes a large or prolonged force to get the truck up to this speed, and it takes a large or prolonged force to bring it to a stop afterwards. If the truck were lighter, or moving more slowly, then it would have less momentum.
>Inertia: Inertia is the resistance of any physical object to any change in its state of motion, including changes to its speed and direction. It is the tendency of objects to keep moving in a straight line at constant velocity.
Right from the start, we can see that if there is no air flowing past the surface of the wing, there is no lift, and thus no takeoff.
The air intake is what pushes the plane forward so that it can gather lift and speed enough for liftoff. There is a mote of truth there though, the wheels aren't strictly necessary. You could put the plane on a slip-and-slide and it would take off, as long as there was enough room for it to build up adequate lift and speed to take off.
Also, once the plane is moving forward under its own engine power, it is no longer on the treadmill and becomes irrelevant to this discussion, considering that it's a discussion about whether a stationary plane on a treadmill can take off.
>If that rod lets go suddenly (or gets cut with a pair of super strong scissors), the plane will fly, though it might be a bit rocky at first.
Here is an experiment:
-Build a paper airplane
-Hold it as you normally would, and drop(NOT throw, drop it straight down) it from somewhere high up
-Observe its flight path, depending on the air temperature and pressure, wind direction etc of your chosen location, it should follow a kind of "J"-shaped curve, falling straight down for a few meters before leveling off and taking a slow, gliding descent
>The point is that momentum[sic] only helps it so much, the main thing that keeps it in the air is the engine
There is one main counter example to this (and the force that keeps the plane moving in a straight line is inertia, not momentum): Planes whose engines have stalled, or otherwise became nonfunctional midflight. If the plane is on a normal, horizontal flight path, it will begin a slow, gliding descent until it either lands, safely or otherwise, or the engine is restarted. If the engine stops, the plane will continue under its own inertia until air friction or collision with the ground or some other force stops it, it won't just fall straight down.
A wing, a parachute, and a sail seem very different at first, but in actuality they all operate in very similar ways, and none of them will move without air flowing over them.
Pictured: Sunny Milk, Luna Child, and Star Sapphire, dressed as Axis soldiers from WWII.
|