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[alway]

Aircraft do not require friction with the ground to accelerate in the same way that a car or bicycle does.  It would accelerate at almost exactly the same rate as it normally and take off with ease.

This. If you, however, were to increase the velocity of the belt to the point where the friction would prevent a plane from moving, the most noticeable effect would be the wheels melting from the heat, and the aircraft then flipping over forward, due to the friction force being unaligned with the forward thrust of the engines. Likely followed by an explosion of slag resulting from the frictional heat instantly melting any part of the aircraft it came into contact with.

To take off, aircraft need air speed; ground speed is entirely irrelevant. It's why aircraft like taking off into a headwind, and hate doing so in a tailwind. A 15 MPH headwind means the aircraft has to have a 15 MPH lower ground speed to take off; the opposite goes for a tailwind. Same goes for landings; for a headwind, you land at a lower groundspeed, and so have to slow down less on the ground; tailwinds require more slowing down. Which is why aircraft carriers try to orient themselves into the wind; it minimizes necessary runway length and takeoff/landing force.

Funfact: in Microsoft Flight Sim X, you can modify wind speeds. If you set it to a headwind above the required airspeed velocity to takeoff in a particular aircraft, you can VTOL that aircraft; be it a tiny 1-seater or a 747. Though, naturally, flying in hurricane force winds has detrimental effects on your ability to fly.

[Sir Finkus]

I think Finkus sounds right.

That's because I am
The conveyer belt is a red herring.  The only parts of the plane that touch the conveyer belt are the wheels.  The wheels are, for the purpose of discussion, free spinning.  Picture pushing a model plane forward on a treadmill.  No matter how fast the treadmill moves, you'll still be able to push the plane forward.  The same thing happens with the plane, except instead of your hand, it uses its engines.

[Ogdibus]

.

[Sheb]

Except the question do specifically say the conveyor is moving fast enough to prevent the plane from moving. So the wheel's friction is enough, which mean alway is right.

[lordcooper]

Except the question do specifically say the conveyor is moving fast enough to prevent the plane from moving. So the wheel's friction is enough, which mean alway is right.

Read it again.  The conveyor belt moves at the same speed as the plane, not the speed required to keep it stationary (there basically isn't one/we can't make anything move that fast).  Reading comprehension is important.

[sneakey pete]

What is it about this question that makes people go all stupid and forget basic physics

[Sheb]

Oh my, you're right. Should have read it with more attention, instead of assuming it was the same I've heard before.

[miauw62]

What is it about this question that makes people go all stupid and forget basic physics

I guess the same thing as with the Monty Hall Problem.

[Sheb]

I've got a funnier one:

"Sleeping Beauty is put to sleep on sunday.
A coin is then tossed to determine which experimental procedure is undertaken. If the coin comes up heads, Beauty is awakened and interviewed on Monday, and then the experiment ends. If the coin comes up tails, she is awakened and interviewed on Monday and Tuesday. But when she is put to sleep again on Monday, she is given a dose of an amnesia-inducing drug that ensures she cannot remember her previous awakening. In this case, the experiment ends after she is interviewed on Tuesday.

Any time Sleeping Beauty is woken and interviewed, she is asked, "What are the odds the coin came up tail?""

[miauw62]

I'll go ahead and say the obvious i guess.

50%

[Hubris Incalculable]

Re: the plane: http://www.youtube.com/watch?v=YORCk1BN7QY

[IronyOwl]

I've got a funnier one:

"Sleeping Beauty is put to sleep on sunday.
A coin is then tossed to determine which experimental procedure is undertaken. If the coin comes up heads, Beauty is awakened and interviewed on Monday, and then the experiment ends. If the coin comes up tails, she is awakened and interviewed on Monday and Tuesday. But when she is put to sleep again on Monday, she is given a dose of an amnesia-inducing drug that ensures she cannot remember her previous awakening. In this case, the experiment ends after she is interviewed on Tuesday.

Any time Sleeping Beauty is woken and interviewed, she is asked, "What are the odds the coin came up tail?""

2/3rds. If she's awake, one of three things happened:

1. The coin came up heads, and it's Monday.
2. The coin came up tails, and it's Monday.
3. The coin came up tails, and it's Tuesday.

Hence, 2:1 odds.

[Ogdibus]

.

[miauw62]

Let's see them do it with an F-14. Those don't blow air across their lift surfaces.  I think they might do more of a rocket car type of thing. Most prop planes do blow air across their lift surfaces, actually.  Most big Boeing and Airbus jets seem to blow air under the wing.  I have now idea if that would be enough.  DC-9s have their engines behind the wings.  The seem as if they might pull air across the top, mostly.  That still seems better than what most fighter jets have.


She would probably take the shape and balance of the coin into greater consideration than the small statistics sample.  After a few years, that might change.

Afaik, F-14's DO blow air across their lift surfaces.
Engine makes plane get speed, speed causes air to flow across lift surfaces, plane goes up.

[Hubris Incalculable]

Let's see them do it with an F-14. Those don't blow air across their lift surfaces.  I think they might do more of a rocket car type of thing. Most prop planes do blow air across their lift surfaces, actually.  Most big Boeing and Airbus jets seem to blow air under the wing.  I have now idea if that would be enough.  DC-9s have their engines behind the wings.  The seem as if they might pull air across the top, mostly.  That still seems better than what most fighter jets have.


She would probably take the shape and balance of the coin into greater consideration than the small statistics sample.  After a few years, that might change.

Afaik, F-14's DO blow air across their lift surfaces.
Engine makes plane get speed, speed causes air to flow across lift surfaces, plane goes up.

in any case, while the air across the lift surfaces is what puts the plane up, the propeller doesn't do enough of that to raise the plane. what is happening is the propeller is dragging the plane forwards against the air, not the ground, so while the ground is moving away from the plane, the plane still moves forward because ot's movement is based entirely on the propeller's pull agaisnt the air. then it moves forward with enough speed that the wings create lift. The only thing the ground changes is the speed that the (unpowered) wheels are spinning at takeoff.