Can the plane take off?

[Bioture]

ok I brought the artillery

I've consulted with my work partner, who owns a plane and can fly a boeing jet on his spare time, as well as a friend who graduated from MIT with a doctorate in mechanical engineering.

my friend who files says: "It doesn't matter how fast the wheels spin. What matters here is the amount of LIFT the wings are receiving. The amount of lift the plane is receiving from the engines alone is not enough for lift off. The plane needs to move against the air to receive the amount of additional lift necessary for take off."

my super smart friend dr. chu says: "Theoretically, the plane would take off if it's moving fast enough to break earth's gravity. Think of firing a bullet, and dropping a clip at the same time. They both fall towards the earth at 9.8m/s. Same with the plane, except it's producing consistent thrust with its engines. This consistent thrust is enough for the plane to stay in the air, but not enough for lift off. If you turned the plane's engines vertically, and then put them on full blast, the plane will not lift off. Let's say that the wheels are spinning at 600mph against a conveyor belt, which is enough for the plane to break earth's gravity, and more than enough for take off. On the conveyor belt, the plane isn't really going 600mph. Its wheels are. It does not break earth's gravity and therefore cannot possibly take off."

[D1st0rt]

[Ewan]

My god.

D1

Your point is completely invalid.

Speed DOES NOT EQUAL FORCE.

The SPEED of the treadmill is going the exact same opposite of the SPEED of the plane. The FORCE of the engine thrust is still FAR GREATER than the FORCE the treadmill applies on the plane in the opposite direction.

Your argument would only be valid if the plane was on skis or the forward thrust came from the wheels being driven.


My toy car analogy, I am talking about speed referenced to the observer. I.e. It takes very little more effort to push the car at 2m/s IN REFERENCE TO THE PERSON PUSHING NOT THE TREADMILL than it does to push it on still ground.


D1, if your physics were true, then if you held a pair of roller skates in one hand, and ran your other hand along the wheels at the bottom, the skates would move with that hand rather than staying where they are.




And WINGS DO NOT WORK BY THE ENGINE SUCKING AIR OVER THEM. If this were the case, gliders and planes with the engines at the rear would not fly.


Now, there will be a small extra amount of thrust / longer runway required, but it will be pretty small (metres / few 100 lbs of thrust)

[Ewan]

my friend who files says: "It doesn't matter how fast the wheels spin. What matters here is the amount of LIFT the wings are receiving. The amount of lift the plane is receiving from the engines alone is not enough for lift off. The plane needs to move against the air to receive the amount of additional lift necessary for take off."

Ok, point out to him a plane's thrust comes from the engines, not the wheels, and he should realise his problem.

[Maurauth]

Who gives a shit about motherfucking planes!

Question 2:
You get a big elevator, with a helicopter in. The helicopter starts to hover, then you turn the elevator on. Will the helicopter go up in the elevator, or just hit the bottom?

[Ewan]

Maur, make a new thread for that, I want to see this argument resolved.

[D1st0rt]

Hmm, I read the question as the speed of the plane and not the speed of the wheels

I shall rethink later, people coming over

[Ewan]

Even if it's speed of the plane, it doesn't have anywhere near as large a force to counteract the thrust from the engines.

[thesearcher]

if the wheels cannot move forwards, how can the plane.

[Aquatiq]

if the wheels cannot move forwards, how can the plane.

wow
http://www.boingboing.net/2006/12/11...admill_pr.html

actually:
http://mouser.org/log/archives/2006/02/001003.html

This discussion ran too long.

[project dragon]

1:Soup du Jour> proj, wanna do me a favour?
1:Soup du Jour> on the forums
1:Soup du Jour> go tell those morons in the conveyor belt/plane thread that it wont take off
1:Soup du Jour> i dont see how that many people can be so stupid

[Aquatiq]

Tell him he has a chance to take it back, LOL.

[Hero*]

The plane cant take off because its "standing" hohooh

[Ewan]

1:Soup du Jour> proj, wanna do me a favour?
1:Soup du Jour> on the forums
1:Soup du Jour> go tell those morons in the conveyor belt/plane thread that it wont take off
1:Soup du Jour> i dont see how that many people can be so stupid

Ewan> aqua
Aquatiq> o/
Ewan> can you forum ban all the "plane won't take off" people pleaseu
Aquatiq> seriously


C 2:Lemmin <ZH>> the "plane on a treadmill" one?
C 2:Ewan> yes
C 2:Lemmin <ZH>> ROFL
C 2:Maurauth> rofl
C 2:Lemmin <ZH>> I can't believe there are so many idiots out there

(lem is on my side)

[Ewan]

what you said about the car ewan makes sense, but think of it like this, as you push the car slightly more, the treadmill moves faster to counter the extra force instantaneously. the treadmill is always going as fast as the wheels, i know this wouldnt be possible in reality, but thats why its a hyperthetical question.

Even if the treadmill is moving backwards at 100mph, it still won't counteract the force of your arm pushing it forwards, it will just make it require a very small extra amount of force.