Yes, we all now know the airplane does infact fly. My last question is this: would it make a differance if the "treadmill" moved 2 or 3 times faster than the plane. A simple yes or no answer will sufice, assuming its from somebody that actually knew the answer to this question. Thanks
obvisouly if the treadmill had no maximum speed, because when the plain started rolling down the runway then the treadmill would speed up.
why wouldent the plain just take off from the taxiway in the first place???
edit: i mean, after the treadmill started doing that?
Originally posted by likeforestDepends if the wheels are considered to have friction or not.
Yes, we all now know the airplane does infact fly. My last question is this: would it make a differance if the "treadmill" moved 2 or 3 times faster than the plane. A simple yes or no answer will sufice, assuming its from somebody that actually knew the answer to this question. Thanks
Originally posted by XanthosNZAt some point the landing gear would snap off or the bearings in the wheels would melt.
No it wouldn't make a difference if the treadmill was going at any finite constant speed. Any discussion of what would happen with infinite speed is pointless as that point all sorts of things happen.
How an aeroplane wing (airfoil) creates lift depends on the pressure differential above and below the wing.
Air flowing over the wing will undergo pressure and speed changes due to the shape of the airfoil, this is because of Bernoulli's principle, which relates the pressure of air to its local velocity. Therfore air flowing across the top of the wing will be at a lower pressure than the air below the wing creating a lift force, increasing the air-velocity will cause this pressure difference to increase, hence increasing the amount of lift.
So in relating to an aeroplane on a treadmill:
The aircraft will have zero local speed and therfore zero airflow over the wing and for that reason there is zero lift
Originally posted by XanthosNZXantoZ wrote:
Not in a thought experiment it won't.
"Any discussion of what would happen with infinite speed is pointless as that point all sorts of things happen."
richjohnson answered:
"At some point the landing gear would snap off or the bearings in the wheels would melt."
XantoZ says that his last posting was of no value:
"Not in a thought experiment it won't."
...when he should've been saying:
"Yes, even that could happen."
...or perhaps...
"All points of things but not exactly this."
...or rather, as he so very often says:
"No, because you're an idiot!"
😵
Originally posted by soulby"But what if the treadmill continues to accelerate? Different story. In principle it's possible to accelerate the treadmill at a rate that will exactly counteract any forward force you care to apply. (This is a departure from the original question, which said the conveyor belt compensated for the plane's speed,, not its force.) The only mathematics needed to demonstrate this is the well-known physics axiom F = ma--that is, force equals mass times acceleration. Given that the conveyor exerts some backward force F on the plane, we simply crank up the acceleration as much as necessary to equal any forward force F generated by its engines. Result: The plane stands still and doesn't take off."
Nevermind
I get it now, the wheels are free spining, interesting puzzle
after reading the other thread (some very rightoeus people out there)
i assume the plane would still take off even if the treadmill accelerated at an equal and opposite rate to the accelerating plane
http://www.straightdope.com/columns/060303.html