No
yeah it does...burton wrote:
that really does not prove anything, the skateboards not on a treadmill which is moving as fast as it, and it doesnt have wings.....Sk wrote:
PLEASE let this video be the end of it....
http://videos.streetfire.net/player.asp … BA1A43A06B
it proves that vehicles that do not rely on their wheels for forward motion, are hardly, if at all, stopped from moving forward if the ground touching their wheels moves in the opposite direction.
It doesn't matter if it has wings... I'm not using it to prove the WHOLE thoery.. I'm using it to prove the part which people have the most doubt about....
Now that this video proves that part, we can safely assume that the jet COULD move forward.
And, as we all know, a jet moving forward will create lift..... and voila.. it WILL take off.
wow, this thread is still up. Seems like a few of you failed your physics class, but its interesting reading how some of you think the plane would fly with no air moving under the wings... Ever seen a plane fly in a vaccuum... thats because its not possible, know what happens when a plane flys into a gas that is lighter than air???? it loses altitude rapidly. An interesting fact, if a pilot flys into methane gas his altimeter will say he is climbing (less airpressure means your higher) but his plane will actually lose altitude.
Because the plane will still need a runway length thing to gain speed.heggs wrote:
then why have a treadmill at all? to start a long discussion that ends with that as an answer? a treadmill is fine, but a runway is cheaper.ATG wrote:
It would have to be runway length, and no, there would not be handles to catch the wings.
The point is, the thrust of the engines will negate the treadmill and the plane will gain speed. The plane would still need speed to create lift under the wings, hence you need a runway sized treadmill.
who the hell mentioned a lack of air??? lol...Locoloki wrote:
wow, this thread is still up. Seems like a few of you failed your physics class, but its interesting reading how some of you think the plane would fly with no air moving under the wings... Ever seen a plane fly in a vaccuum... thats because its not possible, know what happens when a plane flys into a gas that is lighter than air???? it loses altitude rapidly. An interesting fact, if a pilot flys into methane gas his altimeter will say he is climbing (less airpressure means your higher) but his plane will actually lose altitude.
I think it may have been you who failed the physics class my friend
as viper313 proved in his video (and greatly surpassed my earlier googling effort), a plane can move forward on a treadmill that is going as fast as it is... the plane doesn't use the wheels for it's drive.
So, with the FACT that the plane WILL move forward, and because no-one has mentioned this whole experiment is being done in a vacuum, or on the moon or somewhere where the air pressure is not "normal", then it is another known FACT that the aircraft wings will start to generate lift the moment they are moving.
It's then just a matter of time until the aircraft is moving fast enough to get it's wings to generate more lift than the aircraft's pull (or, weight)... and it'll fly........
as it says in the first post:ATG wrote:
Because the plane will still need a runway length thing to gain speed.heggs wrote:
then why have a treadmill at all? to start a long discussion that ends with that as an answer? a treadmill is fine, but a runway is cheaper.ATG wrote:
It would have to be runway length, and no, there would not be handles to catch the wings.
The point is, the thrust of the engines will negate the treadmill and the plane will gain speed. The plane would still need speed to create lift under the wings, hence you need a runway sized treadmill.
so there already IS a runway.. we're all just using a treadmill as a scaled down example......threadstarter wrote:
A plane is standing on a runway that can move
In regards to this scenario, I am assuming the moving runway is at least the size of a normal runway...
but the point is: the treadmill doesn't matter, the ground doesn't matter. the plane will move forward regardless because of its momentum. if the plane is on a treadmill that is its physical length, then the plane will fall off the front. same goes for a plane on a patch of runway its physical length, the plane will fall right off the front of the runway. the wheels merely support the aircraft, that's it.
my mistake was not in thinking that the plane was driven by its wheels, but that because the wheels were frictionless, the plane wouldn't move at all. i failed to take into account the forward momentum that the engines generate. i made the wrongful assumption that the treadmill was slightly longer than the length of the plane.
in conclusion, it doesn't matter what the plane is on. it'll go forward in anything that is frictionless.
so at this point, i agree with you, Sk.
my mistake was not in thinking that the plane was driven by its wheels, but that because the wheels were frictionless, the plane wouldn't move at all. i failed to take into account the forward momentum that the engines generate. i made the wrongful assumption that the treadmill was slightly longer than the length of the plane.
in conclusion, it doesn't matter what the plane is on. it'll go forward in anything that is frictionless.
so at this point, i agree with you, Sk.
Last edited by heggs (2006-12-28 11:59:29)
Remember Me As A Time Of Day
spot onheggs wrote:
but the point is: the treadmill doesn't matter, the ground doesn't matter. the plane will move forward regardless because of its momentum. if the plane is on a treadmill that is its physical length, then the plane will fall off the front. same goes for a plane on a patch of runway its physical length, the plane will fall right off the front of the runway. the wheels merely support the aircraft, that's it.
my mistake was not in thinking that the plane was driven by its wheels, but that because the wheels were frictionless, the plane wouldn't move at all. i failed to take into account the forward momentum that the engines generate.
in conclusion, it doesn't matter what the plane is on. it'll go forward in anything that is frictionless.
(frictionless, or something that generates less friction than the thrust generated by the jets )
disregard my earlier posts, the plane would fly, only its wheels would turn twice as fast while it was taking off
Last edited by Locoloki (2006-12-28 12:04:48)
Actually it's Adams hat. Jamie wears a beret.Sk wrote:
you're getting all my karma for that... and for wearing Jamie's hat in the entire videoviper313 wrote:
OK here it is. Proof of the airplane on a treadmill.
http://video.google.com/videoplay?docid … &hl=en
Thanks for giving people a spot on example and proving our cause!
(my fingers were just about to fall off with all the typing!)
nothing, it would have to start moving forward right before the treadmill starts, or you lose the plane to the scenery.Locoloki wrote:
what keeps the plane from flying off the back of the treadmill?
Remember Me As A Time Of Day
I saw this same question on another forum two or three months ago. It has several hundred pages of people arguing the question. We have a long way to go.
damn you... damn you for being correct! lolviper313 wrote:
Actually it's Adams hat. Jamie wears a beret.Sk wrote:
you're getting all my karma for that... and for wearing Jamie's hat in the entire videoviper313 wrote:
OK here it is. Proof of the airplane on a treadmill.
http://video.google.com/videoplay?docid … &hl=en
Thanks for giving people a spot on example and proving our cause!
(my fingers were just about to fall off with all the typing!)
I like the video
the treadmill would have to be as long as a normal runway though
read nine posts above yours, or the first post of the thread.....Locoloki wrote:
the treadmill would have to be as long as a normal runway though
Look. Airplanes do not use wheels to take off. They use engines to go forward. Going forward creates airflow over the wing. Airflow over the wing creates lift. Lift makes the plane rise up. I'll make some drawings, even.
Here, the plane is traveling 200KPH north. The treadmill is traveling 250KPH south. The plane does not take off, and falls off the back of the treadmill.
Here, the plane is traveling 250KPH north. The treadmill is moving in the opposite direction with the same speed. The plane does not take off - there is no airflow, so there is no lift, so it cannot rise.
Here, the plane is traveling 300KPH north. The treadmill is once again going 250KPH south. The plane travels forward with an airspeed of 50KPH. This is below the minimum takeoff speed, so it does not take off and instead falls off the front of the treadmill.
This is where the plane can finally get off the ground. However, it takes much more fuel than a takeoff off a stationary runway. Here, the plane is traveling at its minimum takeoff speed plus the speed of the treadmill. It requires 250KPH of airflow over the wing to rise. 250 (treadmill speed) + 250 (takeoff speed) = 500, therefore it must travel at 500KPH groundspeed (not treadmillspeed) to take off.
Therefore, the answer is a definitive "Maybe."
Here, the plane is traveling 200KPH north. The treadmill is traveling 250KPH south. The plane does not take off, and falls off the back of the treadmill.
Here, the plane is traveling 250KPH north. The treadmill is moving in the opposite direction with the same speed. The plane does not take off - there is no airflow, so there is no lift, so it cannot rise.
Here, the plane is traveling 300KPH north. The treadmill is once again going 250KPH south. The plane travels forward with an airspeed of 50KPH. This is below the minimum takeoff speed, so it does not take off and instead falls off the front of the treadmill.
This is where the plane can finally get off the ground. However, it takes much more fuel than a takeoff off a stationary runway. Here, the plane is traveling at its minimum takeoff speed plus the speed of the treadmill. It requires 250KPH of airflow over the wing to rise. 250 (treadmill speed) + 250 (takeoff speed) = 500, therefore it must travel at 500KPH groundspeed (not treadmillspeed) to take off.
Therefore, the answer is a definitive "Maybe."
I just had an epiphany, ATG said the tread mill would respond to forward momentum of the plane so if the plane could never move forward the tread mill would never start!! is that smoke coming from your ears
Last edited by Valium500mg. (2006-12-28 12:29:09)
Fact Given Enough Run Way And Enough Power Even A 57 Chevy Will Fly
No, it won't. Just because something's in the air doesn't mean it's flying. If I toss a pencil into the air, it's not flying. If I throw a basketball, it's not flying.Valium500mg. wrote:
Fact Given Enough Run Way And Enough Power Even A 57 Chevy Will Fly
An F-14 can fly. A hummingbird can fly. Anything that generates lift can fly. Anything that doesn't can get into the air - but it won't fly.The Wikipedia article on "flight" wrote:
Flight is the process by which an animal or object achieves sustained movement either through the air by aerodynamically generating lift or aerostatically using buoyancy, or movement beyond earth's atmosphere, in the case of spaceflight.
yep.. it must travel at 500kph RELATIVE GROUND SPEED...k30dxedle wrote:
Look. Airplanes do not use wheels to take off. They use engines to go forward. Going forward creates airflow over the wing. Airflow over the wing creates lift. Lift makes the plane rise up. I'll make some drawings, even.
http://img.photobucket.com/albums/v724/ … llslow.png
Here, the plane is traveling 200KPH north. The treadmill is traveling 250KPH south. The plane does not take off, and falls off the back of the treadmill.
http://img.photobucket.com/albums/v724/ … lequal.png
Here, the plane is traveling 250KPH north. The treadmill is moving in the opposite direction with the same speed. The plane does not take off - there is no airflow, so there is no lift, so it cannot rise.
http://img.photobucket.com/albums/v724/ … llfast.png
Here, the plane is traveling 300KPH north. The treadmill is once again going 250KPH south. The plane travels forward with an airspeed of 50KPH. This is below the minimum takeoff speed, so it does not take off and instead falls off the front of the treadmill.
http://img.photobucket.com/albums/v724/ … illrog.png
This is where the plane can finally get off the ground. However, it takes much more fuel than a takeoff off a stationary runway. Here, the plane is traveling at its minimum takeoff speed plus the speed of the treadmill. It requires 250KPH of airflow over the wing to rise. 250 (treadmill speed) + 250 (takeoff speed) = 500, therefore it must travel at 500KPH groundspeed (not treadmillspeed) to take off.
Therefore, the answer is a definitive "Maybe."
but that's still only 250kph TRUE GROUND SPEED.
as a jet aircraft generates AIR speed, not GROUND speed, it could need to achieve a relative ground speed equal to the speed of light... but that would STILL be 250kph AIR speed...
look at it from another point of view.... if the aircraft was already airborne and landed on the very same treadmill... would it come to a complete stop the moment the wheels touched down (lets assume the jet lands at 250kph exactly, and the treadmill is travelling at exactly 250kph in the other direction) ?
no.. of course it wouldn't... this is because the jet has an AIR speed of 250kph, and (at the point of landing), it's RELATIVE ground speed would be 500kph.
So.. now we can (hopefully) agree the aircraft wouldn't come to an immediate stop...
lets also assume the jet maintains EXACTLY the same thrust from its jets (the same it had when it was flying, the same it has when it touches down again on the treadmill), the jet can again pull up and take off.
This is because it's TRUE groundspeed is STILL 250kph and is unchanged by the treadmill..
Yes, ok.. it would loose SOME speed from the friction on touchdown, but it would still have over 200kph of forward thrust...
again... try it yourself...
grab a toy car... hold it above a treadmill... "swoop" it down onto then off the treadmill....
you'll find that it only takes a little bit more effort to keep your "swoop" moving at the same speed once you do touch the treadmill....
real-life example would be an aircraft carrier.... if it's travelling north at 50kph GROUND speed, and a jet did a "touch and go" on it, whilst maintaining an AIR speed of 250kph, then before it touches the carrier, its RELATIVE ground speed would be 250kph, as soon as it's over the carrier, it's RELATIVE GROUND speed would only be 200kph... as when it touches down, and when it takes off again, and as soon as it's off the back of the carrier, it's RELATIVE ground speed will be 250kph again.
throughout the entire "touch and go", it's TRUE ground speed will drop only a few kph when it's wheels touch... and then it'll be back up again almost as soon as it's wheels leave the ground...
same goes for it's TRUE AIR speed.
what doesn't change throughout the whole thing is the amount of thrust being generated by the engines, nor the lift that COULD be generated by the wings (allowing for the SMALL change upon landing).
think about it.... if a plane was in a headwind of 250kph on the ground, and the plane was stationary, it would have a ground speed of 0kph, but (as we have agreed 250kph is enough speed for takeoff) the pilot could simply pull back slightly and the plane would leave the ground... still having a ground speed of 0kph...
infact, if the pilot dropped the thrust a bit, he could STILL be gaining alititude and FLYING, but have a ground speed in negative numbers...
same principal of you holding a kite...
so... like I say, ground speed has ABSOLUTELY NOTHING to do with the jet's ability to move forward, as it's propulsion systems DO NOT GENERATE GROUND SPEED, unlike a car, who's engine has driveshafts, that attach to the wheels and directly drives them.
Last edited by Sk (2006-12-28 13:05:56)
how can a retarded question like this be discussed for so long, of course it'll take off
imagine yourself sitting in a wheelchair (or something) on a treadmill and you try rolling forward by pushing its wheels, this represents the car on a treadmill, the faster the treadmill runs the faster you gotta push to stop you from falling off
now, instead imagine that you're holding a wire attached to something in front of the treadmill, this represents the airplane and how it pushes air to move forward, you just pull the wire and start moving forward regardless if the treadmill is standing still or doing 100kph (obviously you have to overcome the friction of the spinning wheels but that is irrelevant in this case)
imagine yourself sitting in a wheelchair (or something) on a treadmill and you try rolling forward by pushing its wheels, this represents the car on a treadmill, the faster the treadmill runs the faster you gotta push to stop you from falling off
now, instead imagine that you're holding a wire attached to something in front of the treadmill, this represents the airplane and how it pushes air to move forward, you just pull the wire and start moving forward regardless if the treadmill is standing still or doing 100kph (obviously you have to overcome the friction of the spinning wheels but that is irrelevant in this case)
Damn! Outta popcorn.
KJ
KJ
The quick way to tell the truth[RFW]Xenomorph wrote:
how can a retarded question like this be discussed for so long, of course it'll take off
imagine yourself sitting in a wheelchair (or something) on a treadmill and you try rolling forward by pushing its wheels, this represents the car on a treadmill, the faster the treadmill runs the faster you gotta push to stop you from falling off
now, instead imagine that you're holding a wire attached to something in front of the treadmill, this represents the airplane and how it pushes air to move forward, you just pull the wire and start moving forward regardless if the treadmill is standing still or doing 100kph (obviously you have to overcome the friction of the spinning wheels but that is irrelevant in this case)
I can't believe this is still being discussed. I have already proven it. See the link above!viper313 wrote:
OK here it is. Proof of the airplane on a treadmill.
http://video.google.com/videoplay?docid … &hl=en