Does it fly? I say yes it does.

Does it fly? I say yes it does.

I have to be missing something here right? A URL missing or a picture?? :bomb:

The propeller pushes air, not tarmac. It'll be a lot harder, but as the plane starts moving forward (relative to the ground itself) and gets more air under its wings, the friction with the treadmill will become less and less until the treadmill doesn't matter at all (and, of course, it'd be flying).

I have to be missing something here right? A URL missing or a picture?? :bomb:
I think he's talking about this question: if a plane is put on a treadmill and the treadmill moves at the speed of the plane, trying to keep the plane in its original position relative to the ground to the extent that it's able, will the plane be able to take off?

Unless there are specifications I'm not familiar with, it's assumed that the plane has sufficient/unlimited power and the treadmill has sufficient/unlimited speed.

Here is one. There are many urls on google.

Imagine a plane is sitting on a massive conveyor belt, as wide and as long as a runway, and intends to take off. The conveyer belt is designed to exactly match the speed of the wheels at any given time, moving in the opposite direction of rotation.

Can the plane take off?

mythbusters did it.

oh. . . and it didn't work.

mythbusters did it.

oh. . . and it didn't work.

Doesn't that episode air on the 30th? :sneaky:

The propeller pushes air, not tarmac. It'll be a lot harder, but as the plane starts moving forward (relative to the ground itself) and gets more air under its wings, the friction with the treadmill will become less and less until the treadmill doesn't matter at all (and, of course, it'd be flying).

Surely this assumes that the only thing holding the plane on the ground is friction. This seems to forget a little thing called gravity.

Isn't the concept of flight based on developing a high pressure area under the wing and a low pressure area above the wing such that the wing is forced up into the low pressure area ?

The only way you can make this happen is by air movement around the wing. The plane sitting stationary does not develop any air movement.

Stand next to a helicopter when it takes off - the amount of air movement you experience is significant.

Oh puleease God, not here too. :(:(:(:(:(:

Do we really have to suffer this debate yet again?

Surely this assumes that the only thing holding the plane on the ground is friction. This seems to forget a little thing called gravity.
The only thing that keeps it in place (horizontally) is friction from the wheels (and inertia). Vertical gravity isn't important except as a component of the normal force on the tires from the treadmill which is a component of friction.

I would expect an aircraft to be able to push off of air and be able to gain a forward thrust much quicker than its wheels and friction could generate a negative motion/thrust. I don't know about a Cessna necessarily, but put an F-22 (thrust/weight ratio of 1.26) on a conveyor belt and you can't tell me that a plane that can ACCELERATE going directly against gravity can't gain speed on a treadmill.

I know the plane would need to gain speed relative to the air and not just wheels spinning on a rotating treadmill, but if the forward/backward thrust ratio is greater than 1, it'll eventually get there (or fall off the treadmill).

No way the plane flys. The wings need lift, which is caused by air going over/under the wing. This would be like a car on a dyno going airborne.

Look at this graph and you'll clearly see that I'm obviously correct. :shiner:

http://www.g8board.com/forums/attachment.php?attachmentid=351&d=1201212668

no it does not... =)

chrish

Actually, I think any air-worthy plane would be able to take off.

If the plane had its brakes on, it would be very hard to take off. An F-22 could do it while ripping apart its tires, but at least some other planes would have too much resistance from their tires.

However, if the planes allow their wheels to be free-spinning, they will require just above what it would normally take them to accelerate. When a plane accelerates, it must overcome its inertia and account for the friction on its wheels. Now, if the treadmill was spinning backward as fast as the plane was going forward, the net result would be that the plane would lift off of the ground with its wheels turning twice as fast as they would be relative to solid ground.

on solid ground: inertia + normal friction of wheel spin on axle
on conveyor: inertia + 2x (normal friction of wheel spin on axle)

It might depend on the plane, but the friction of the wheel spin is so small that it should be negligible.

The first time I thought about it, I forgot the the treadmill is as long as a runway.

There seems to be a debate as to whether the wheels would be moving twice as fast as the plane was relative to the ground.. or whether the treadmill is moving infinitely fast as soon as the plane moves forward at all. I think it depends on how you define the speed of the treadmill relative to the wheels.

If the speed of the treadmill equals the speed of the wheels relative to the plane, then they'll both move towards infinity real fast. The plane will budge forward, which will turn the wheels, which will then turn the treadmill, which will require the wheels to go faster, so the treadmill will have to go faster... until the treadmill blows up and/or the wheels fall off.

If the speed of the treadmill equals the speed that the wheels are moving away from a given point on the ground, they will be spinning twice as fast as if they were on solid ground.

It doesn't matter how fast the wheels are spinning, it'll take off. The plane exerts force on air to move, not through spinning tires.

Hey people are cheating. They are replying and not voting. Over at LS1GTO we don't have the option of creating a thread with votes.

Please don't try this at home. You will break thru the time warp continum and find yourself in a Ford. :eek2:

No, it does not. If you run on a treadmill do you feel the breeze?

I stationary plane would "take off" in a wind tunnel though.

LOL... I can't believe anyone would think it would work. Planes fly due to air pressure, there is none if the plane isn't moving through the air...

A Treadmill is a moving platform. So if a plane stands on one, and the wheels start spinning, how does this equate lift? The wheels don't make an air plane fly.... if so, once retracted, the plane would crash....

The jet does not take off due to moving air, it takes off when it is moving fast enough that the air pressure beneath the wings is able to lift the plan off of the ground. You could move the ground beneath as fast as you want. But it is air-speed (the speed through the air, not relative to the ground) that promotes lift...

For example, does a car on a dyno all day long at top speed make it to grandmas house and back? Fat chance...

No, it does not. If you run on a treadmill do you feel the breeze?

I stationary plane would "take off" in a wind tunnel though.
If you run an airplane on a treadmill you do. :boink:

The plane isn't going to be stationary, though; it's not locked-down to a spot.
The prop/jet engine will push off air and begin moving forward, as would a plane on a solid surface.


The question isn't meant to imply a small treadmill; most say on a treadmill as long and as wide as an air strip. The plane isn't bound to a spot in any way. I think that's a common misunderstanding of the pretenses.

LOL... I can't believe anyone would think it would work. Planes fly due to air pressure, there is none if the plane isn't moving through the air...

A Treadmill is a moving platform. So if a plane stands on one, and the wheels start spinning, how does this equate lift? The wheels don't make an air plane fly.... if so, once retracted, the plane would crash....

The jet does not take off due to moving air, it takes off when it is moving fast enough that the air pressure beneath the wings is able to lift the plan off of the ground. You could move the ground beneath as fast as you want. But it is air-speed (the speed through the air, not relative to the ground) that promotes lift...

For example, does a car on a dyno all day long at top speed make it to grandmas house and back? Fat chance...

The plane's on a big-ass treadmill and free to move about as it is able. The question isn't asking if a treadmill can put an airplane in the sky, it's asking if a plane could overcome a treadmill and get itself in the sky.

A lot of people that say no say so because, well, they think an airplane puts its power through its wheels on take-off and a treadmill could negate that.

Someone owes me $21.99 because my treadmill threw my plane to the ground and it broke into 50 pieces.:damnyou:

As mentioned b4, it depends on what the question is asking. If the planes engins are of the OF COURSE NOT-

If the engines are on then theoretically yes of course it will. It stumps most car nuts because the wheels do not power a plane. Thus any comparisons to cars or dynos is irrelevant.

If its a model plane, then probably not, because there isnt much thrust to overcome wheel friction. Most of the experiments use models with tredmills already running which is a double whammy since the tredmil should start of slowly and spin only as fast as the wheels would have spun naturally upon normal takeoff.

A light plane- i dont know, a jet, yes.

A lot of ppl seem to think "no" because they are thinking of a plane taking off on the spot (because they think its powered by the wheels). Its not supposed to take off on the spot, its sposed to accellerate down the runway as per normal, wheel speed is irrellevant except in wheel friction.

Same concept as a seaplane taking off up a fast river- although the seaplane has more friction to contend with than a wheeled plane on a treedmill would, so its harder.

Seriously guys, planes move by applying force on AIR. AIR!!!!!!!!! The only thing the ground does is keep the plane from dropping any lower. Tires spin freely (with some friction). Sure, it'll take a hair longer to take off because of the added friction of tires spinning faster, but it will take off. I assure you.

27 replys in less than 12 hours. It is obvious that many of us have too much free time and need a hobby.....or serious counciling. :damnyou:

It will take off if I'm onboard.....nothing will stop me from taking my holiday

Its an unanswerable question folks!

The problem is stated in an intentionally vague way, in that it does not specify the airplane's speed relative to what....the air or the treadmill... It's intended to spark an unlimited debate between the deaf, blind, and mute.

You can't answer the question until you know what the airplane's speed is relative too.

Also, it depends on the gear ratio in the airplane's rear end....lol.

Only a CV-22 Osprey (tilt wing)

Here's the proof against. Take a Wright Brother's kite and simply hold it in your hand when or where there is absolutely no wind or air movement. Let go of it, but watch out for your toes, cause it'll drop. Airplanes fly AGAINSTALL ODDS, because of lift. And you don't have to change air pressure both above and below the wing, only create a difference. Standard airfoil shape http://upload.wikimedia.org/wikipedia/commons/thumb/1/17/Airfoil.svg/350px-Airfoil.svg.png lengthens the travel distance of air above the wing compared to below, decreasing pressure above, creating lift. An airfoil or wing cannot generate lift without movement of either th ewing through the air, or air across the wing (think air tunnel). A tethered to teh ground Cessna could technically "fly" if th ewind is strong enough - but the hypothethis of a plane on a treadmill must rule out any nominal wind speed to be considered - and guess what, any person that believes that a stationary relative to air lifting body will lift (helos excluded as we are talking planes) should sue their hometown educational institution for malfeasance, misrepresentatioin, and high charge of producing town idiots.

Even a propeller driven plane cannot move enough air past the wings with enough volume and velocity to not only create lift, but also to create enough power to turn the planes wheels fast enough to even get the treadmill moving in the first place. Oh? you thought the treadmill was powered? Just like a car dyno???????? Hah, double hah.

Even the most powerful airplanes on the planet cannot take off from teh deck of the USS Enterprise without a little steam enhanced swat on the behind.

The plane doesn't stay in one place. It is allowed to go forward. The treadmill is as long as a runway.

Not this **** again. :banghead:

The plane moves because the engines create force against the air, no matter how fast or in what direction the air is moving. Think of it like some arm reaches down and pushes on the back of the engine. No matter how fast the treadmill is moving in the opposite direction, the plane will move forward, eventually fast enough to create lift and take off.

It is absolutely an answerable question. And the answer is "Yes, the plane will take off." No ifs ands or buts.

Aircraft carriers use the steam launchers to ensure the planes achieve anough speed to fly before they fall off the end of the deck and sleep with the fishes. It's insurance.

Well, the way the vague phrase was worded, it seemed as if someone was suggesting that a jet sitting on a treadmill will just start to fly if the treadmill started moving faster without using engines. This works for paper planes....

Obviously, everyone already knows a jet can fly. So the treadmill part is just kinda.......:offtheair::offtheair:

Only a CV-22 Osprey (tilt wing)

Here's the proof against. Take a Wright Brother's kite and simply hold it in your hand when or where there is absolutely no wind or air movement. Let go of it, but watch out for your toes, cause it'll drop. Airplanes fly AGAINSTALL ODDS, because of lift. And you don't have to change air pressure both above and below the wing, only create a difference. Standard airfoil shape http://upload.wikimedia.org/wikipedia/commons/thumb/1/17/Airfoil.svg/350px-Airfoil.svg.png lengthens the travel distance of air above the wing compared to below, decreasing pressure above, creating lift. An airfoil or wing cannot generate lift without movement of either th ewing through the air, or air across the wing (think air tunnel). A tethered to teh ground Cessna could technically "fly" if th ewind is strong enough - but the hypothethis of a plane on a treadmill must rule out any nominal wind speed to be considered - and guess what, any person that believes that a stationary relative to air lifting body will lift (helos excluded as we are talking planes) should sue their hometown educational institution for malfeasance, misrepresentatioin, and high charge of producing town idiots.

Even a propeller driven plane cannot move enough air past the wings with enough volume and velocity to not only create lift, but also to create enough power to turn the planes wheels fast enough to even get the treadmill moving in the first place. Oh? you thought the treadmill was powered? Just like a car dyno???????? Hah, double hah.

Even the most powerful airplanes on the planet cannot take off from teh deck of the USS Enterprise without a little steam enhanced swat on the behind.
Recommend hobby, counseling........and heavy medication! :sneaky:

Obviously, everyone already knows a jet can fly. So the treadmill part is just kinda.......:offtheair::offtheair:
Yes, but it creates a heated debate with people that know what they're talking about that understand the issue, people that know what they're talking about but misunderstand the issue, people that don't know what they're talking about but understand the issue, and people that neither know what they're talking about nor understand the issue.
Basically, it mirrors a political debate. :eek2:

Yes, but it creates a heated debate with people that know what they're talking about that understand the issue, people that know what they're talking about but misunderstand the issue, people that don't know what they're talking about but understand the issue, and people that neither know what they're talking about nor understand the issue.
Basically, it mirrors a political debate. :eek2:
With the caveat that in a political debate NOBODY knows what they're talking about. :drool: :drool: :drool: :sneaky:

OK OK...i solved the question...this plane can.....




http://www.tollway.com/oshkosh/HARRIER.JPG

what do i win?

i agree with above! i forgot about the harrier jet!

chrish

That's actually the basic reason as to why the plane will in fact take off. Thrust against air will make it move.

Its an unanswerable question folks!

The problem is stated in an intentionally vague way, in that it does not specify the airplane's speed relative to what....the air or the treadmill... It's intended to spark an unlimited debate between the deaf, blind, and mute.

You can't answer the question until you know what the airplane's speed is relative too.

Also, it depends on the gear ratio in the airplane's rear end....lol.

FINALLY! I've been trying to say this over at the 'other' place for weeks.

However, if you do take the position that the planes speed is taken relative to the ground (air), NOT the conveyor, then the question is really not that interesting.

OK let’s get rid of the wheels and replace them with skis. Then let’s cover the treadmill with snow. What is going to keep the plane from going forward? There is no friction on snow. It doesn’t matter how fast you move the treadmill in reverse. The plane will just go forward.

Not this **** again. :banghead:

Hahahhaha.......I vote to shoot the next poster who continues this thread with a treadmill content. However, my question is this.........does a .44 shell hit it's target faster than a .33...........and if so, does the OP endure more brain splatter than the .33 (me) shooter?

Hahahhaha.......I vote to shoot the next poster who continues this thread with a treadmill content. However, my question is this.........does a .44 shell hit it's target faster than a .33...........and if so, does the OP endure more brain splatter than the .33 (me) shooter?

with the same grain load, and same barrell length, no, unless the .44 has less mass than the .33 .......... or unless the .33 is shot at an upward angle of 45 degrees and the .44 is shot at an elevation of......or is this Dirty Harry's .44, and did he shoot 7 or 8 and do you feel lucky, punk?


(see, no treadmill comment, ....oops)



Giga, you have obviously never been on skis in snow. If there were no traction you couldn't turn or stop.

Would this take off on a treadmill?

http://www.history.navy.mil/pics/v22.jpg

LOL!

with the same grain load, and same barrell length, no, unless the .44 has less mass than the .33 .......... or unless the .33 is shot at an upward angle of 45 degrees and the .44 is shot at an elevation of......or is this Dirty Harry's .44, and did he shoot 7 or 8 and do you feel lucky, punk?


(see, no treadmill comment, ....oops)



Giga, you have obviously never been on skis in snow. If there were no traction you couldn't turn or stop.

If you turn the ski sideways there is traction or friction.

So a plane on a what will do what if its which?:eek2: I must be a the Popular Mechanics site!!!:confused: I thought this site was about the Pontiac G8!!:angel:

So a plane on a what will do what if its which?:eek2: I must be a the Popular Mechanics site!!!:confused: I thought this site was about the Pontiac G8!!:angel:

So, if you strap a G8 to a dyno, and accelerate, will it reach 60 mph anytime soon?

Mythbusters is doing this one on Wednesday. I guess we'll find out what 6 of us already know.

Fly away boys, fly away!

So, if you strap a G8 to a dyno, and accelerate, will it reach 60 mph anytime soon?

Why waste the time on a dyno when you could be driving it?:thumbsup:

Why waste the time on a dyno when you could be driving it?:thumbsup:

Its not going anywhere....especially if its on a treadmill
:coffee:

Its not going anywhere....especially if its on a treadmill
:coffee:

Like I said Olly, its wasted on a treadmill! Take that sucker out and drive it!:driving:

Mythbusters is doing this one on Wednesday. I guess we'll find out what 6 of us already know.

Cool! Mythbusters rock!!!

Would this take off on a treadmill?

http://www.history.navy.mil/pics/v22.jpg

LOL!

It might take off but then it would probably crash after getting 10 feet off the ground.

Hahahhaha.......I vote to shoot the next poster who continues this thread with a treadmill content. However, my question is this.........does a .44 shell hit it's target faster than a .33...........and if so, does the OP endure more brain splatter than the .33 (me) shooter?
I volunteer to do the wet work on this side of the pond. I think my S&W .40 Glock would be a good compromise betwixt the .33 & the .44.............not too sure we need to be concerned about brain splatter, however. :nuts:

Today is the day.

Today is the day.

Mythbusters, tonight at 9:00PM (at least EST) on Discovery

Lets hope they don't screw it up!

woot

The minority wins!!!

I really couldn't believe the pilot they hired. He should probably have his license revoked for having such little knowledge of the physics involved in flight; isn't that type of knowledge required?

Yea we win!!!!!!