Mythbusters punk'd whole internet

[Squisher]

As I posted in the other two threads:

If I'm flying a plane at 200mph and I hang out of it and affix a treadmill to the wheels which cause the wheels to spin at a rate that would generate a speed of 200mph backwards. Will the plane fall out of the sky?

 

[BlackTigers]

Originally posted by: Squisher
As I posted in the other two threads:

If I'm flying a plane at 200mph and I hang out of it and affix a treadmill to the wheels which cause the wheels to spin at a rate that would generate a speed of 200mph backwards. Will the plane fall out of the sky?

Sure, if the treadmill was heavy enough.

 

[bignateyk]

Originally posted by: Squisher
As I posted in the other two threads:

If I'm flying a plane at 200mph and I hang out of it and affix a treadmill to the wheels which cause the wheels to spin at a rate that would generate a speed of 200mph backwards. Will the plane fall out of the sky?

no, because the plane is still moving at a speed relative to the ground, which will cause air to flow over the wings and the plane to have lift.

If the treadmill is on the ground and the plane has a ground speed of 0mph, then there will be no air flow over the wings, and no lift.

 

[dainthomas]

Originally posted by: Fritzo

Originally posted by: MasonLuke

Originally posted by: BoberFett

Originally posted by: mrSHEiK124

Originally posted by: waggy

Originally posted by: smack Down

If the plane is going backwards then it would mean that the treadmill is no longer matching the wheel speed of the plane. The treadmill would have to be going faster then the wheels. Stop think of the plane as something special just think of it like a car.

thats the problem. THIS IS NOTHING LIKE A CAR.

really its not. a car gets its thrust by the wheels. a plane by the thrust of the engines.

For every action, there is an equal and opposite reaction. the thrust of the engine has to have its opposite action. the wheels/treadmill ARE NOT IT.

Thank you, best explanation ever.

THE AIRPLANE TAKES OFF. The wheels moving backwards, forwards, sideways; fuck, take off the wheels and make the damn plane slide across the treadmill, IT WILL TAKE OFF. None of the forces I just mentioned would do ANYTHING to counter the thrust of the jet engines. NOTHING.

Wrong. Until there is sufficient lift to get the plane off it's wheels, it's speed IS it's ground speed and IS dependent on the wheels. Unfortunately when there's a conveyor belt that is matching it's ground speed in the opposite direction, the ground speed relative to the conveyor will rise but it's ground speed relative to the actual ground would be zero. And since the actual ground speed is zero the air speed (the speed of the air running under/over the wings) will never be enough to cause lift.

Thank you. This is the logical answer and the only answer!

That's what I was saying, and three people called me an idiot. It hurt my feelings.

This bass-ackwards logic hurts MY feelings. Big meanie! :|

 

[Auric]

Originally posted by: Squisher
As I posted in the other two threads:

If I'm flying a plane at 200mph and I hang out of it and affix a treadmill to the wheels which cause the wheels to spin at a rate that would generate a speed of 200mph backwards. Will the plane fall out of the sky?

Of course the plane will crash and burn. Its aerodynamics have been buggered by the treadmill. You (as pilot) will prolly get a bird strike in the face too.

 

[bignateyk]

Originally posted by: dainthomas

Originally posted by: Fritzo

Originally posted by: MasonLuke

Originally posted by: BoberFett

Originally posted by: mrSHEiK124

Originally posted by: waggy

Originally posted by: smack Down

If the plane is going backwards then it would mean that the treadmill is no longer matching the wheel speed of the plane. The treadmill would have to be going faster then the wheels. Stop think of the plane as something special just think of it like a car.

thats the problem. THIS IS NOTHING LIKE A CAR.

really its not. a car gets its thrust by the wheels. a plane by the thrust of the engines.

For every action, there is an equal and opposite reaction. the thrust of the engine has to have its opposite action. the wheels/treadmill ARE NOT IT.

Thank you, best explanation ever.

THE AIRPLANE TAKES OFF. The wheels moving backwards, forwards, sideways; fuck, take off the wheels and make the damn plane slide across the treadmill, IT WILL TAKE OFF. None of the forces I just mentioned would do ANYTHING to counter the thrust of the jet engines. NOTHING.

Wrong. Until there is sufficient lift to get the plane off it's wheels, it's speed IS it's ground speed and IS dependent on the wheels. Unfortunately when there's a conveyor belt that is matching it's ground speed in the opposite direction, the ground speed relative to the conveyor will rise but it's ground speed relative to the actual ground would be zero. And since the actual ground speed is zero the air speed (the speed of the air running under/over the wings) will never be enough to cause lift.

Thank you. This is the logical answer and the only answer!

That's what I was saying, and three people called me an idiot. It hurt my feelings.

This bass-ackwards logic hurts MY feelings. Big meanie! :|

Dont worry fritzo, youre not the idiot.

The thrust of a plane and the lift are two completely independent elements. The purpose of the thrust is to get the plane moving foward. Why? SO THAT AIR FLOWS OVER THE WINGS. If there is no air flowing over the wings, the plane won't take off. Its really not a difficult concept.

If an airplane is on a treadmill with a ground speed of 0 mph the entire time, it will at no point take off. If you allow the plane to move on the treadmill (thereby giving it a positive speed relative to ground), then it is a completely different problem, and the plane COULD take off.

 

[randay]

for fucks sake why is this so hard to understand?

A TREADMILL CANNOT STOP AN AIRPLANE FROM MOVING FORWARD.

 

[spidey07]

Originally posted by: randay
for fucks sake why is this so hard to understand?

A TREADMILL CANNOT STOP AN AIRPLANE FROM MOVING FORWARD.

Why not?

It's already been shown that it can move it backwards. Seriously, just think about it it. If the treadmill can move a plane backwards then all you have to do is speed it up to move it backwards with more force. As long as this is equal to the thrust of the plane - the plane isn't going anywhere.

 

[AMCRambler]

So did they do it yet or what? I can't wait to say I told you so. That thing is gonna sit on the conveyor belt and not go anywhere. There I said it. Now when it comes true I can be like boo yah and quote myself.

 

[randay]

Originally posted by: spidey07

Originally posted by: randay
for fucks sake why is this so hard to understand?

A TREADMILL CANNOT STOP AN AIRPLANE FROM MOVING FORWARD.

Why not?

It's already been shown that it can move it backwards. Seriously, just think about it it. If the treadmill can move a plane backwards then all you have to do is speed it up to move it backwards with more force. As long as this is equal to the thrust of the plane - the plane isn't going anywhere.

and thats where you have all gone wrong. you take the conclusion that the airplane can be stopped, then work backwards adding things and ignoring others to create a situation where that happens. even if we assume the treadmill is capable of infinite and instant acceleration and speed, all we have to do is add friction, and the tires just smoke and the airplane takes off anyway.

 

[SnipeMasterJ13]

Originally posted by: spidey07

Originally posted by: randay
for fucks sake why is this so hard to understand?

A TREADMILL CANNOT STOP AN AIRPLANE FROM MOVING FORWARD.

Why not?

It's already been shown that it can move it backwards. Seriously, just think about it it. If the treadmill can move a plane backwards then all you have to do is speed it up to move it backwards with more force. As long as this is equal to the thrust of the plane - the plane isn't going anywhere.

You can move a plane backwards on a treadmill if you move the treadmill slowly. That is because there IS a small amount of friction in the bearings. Same thing applies to a table cloth with plates on it. Slowly pull the table cloth, and the plates go with. But, if you yank the table cloth out quickly, the friction is not enough to keep the plates on the table cloth.

So all we need for the plane to take off is to have the thrust of the engines > friction in bearings. Tens of thousands of lbs of thrust is more than enough for this, so, plane takes off.

Along the lines of a treadmill COULD stop one. Yes, if it was moving at super insane speeds that are not even possible. So, if you have a treadmill that can move at the speed of light, you may have a chance. But if you are thinking along those lines, you will most likely have frictionless bearings, so the plane would STILL take off.

 

[AMCRambler]

Originally posted by: randay

Originally posted by: spidey07

Originally posted by: randay
for fucks sake why is this so hard to understand?

A TREADMILL CANNOT STOP AN AIRPLANE FROM MOVING FORWARD.

Why not?

It's already been shown that it can move it backwards. Seriously, just think about it it. If the treadmill can move a plane backwards then all you have to do is speed it up to move it backwards with more force. As long as this is equal to the thrust of the plane - the plane isn't going anywhere.

and thats where you have all gone wrong. you take the conclusion that the airplane can be stopped, then work backwards adding things and ignoring others to create a situation where that happens. even if we assume the treadmill is capable of infinite and instant acceleration and speed, all we have to do is add friction, and the tires just smoke and the airplane takes off anyway.

Well that is the crux of the argument right there. Can a treadmill stop a plane from moving forward? I would think it all depends on friction between the wheels and the plane. If the wheels spin freely on their axles and there is no friction there, then you're right. It won't stop a plane from moving forward once the engines are on. Right?
If there is friction between the wheels and the axles, then the plane might roll a bit, but it's gonna go backwards fastert than it can roll. So does the original question state friction or no-friction? If it doesn't, you can't answer the question.

 

[mugs]

Originally posted by: AMCRambler
So did they do it yet or what? I can't wait to say I told you so. That thing is gonna sit on the conveyor belt and not go anywhere. There I said it. Now when it comes true I can be like boo yah and quote myself.

And now we can do the same when you're wrong. (go ahead and quote this so I can't change it)

 

[randay]

Originally posted by: mugs

Originally posted by: AMCRambler
So did they do it yet or what? I can't wait to say I told you so. That thing is gonna sit on the conveyor belt and not go anywhere. There I said it. Now when it comes true I can be like boo yah and quote myself.

And now we can do the same when you're wrong. (go ahead and quote this so I can't change it)

+1 i was actually gonna stick a bunch of these into my sig but i didnt want to hurt certain peoples feelings more then they already are.

 

[JujuFish]

I can't believe this argument is still going on. The plane takes off.

 

[LTC8K6]

It's already been shown that it can move it backwards.

No one has shown that the conveyor can move the plane backwards if the pilot is trying to taxi or take off.

 

[NanoStuff]

Originally posted by: JujuFish
I can't believe this argument is still going on. The plane takes off.

Yes sir captain stupid.

 

[angminas]

Plane speed relative to the ground doesn't matter. The ground, wheels, conveyor belt, instrument readings, and the plane at large are all red herrings. What really matters is wing speed relative to airmass. If the wings are moving fast enough relative to the air flowing over them from front to back, the plane will take off. If not, it won't. With this in mind, you could set it up to do just about whatever you wanted it to, which is why it's important to remember that Mythbusters and ATOT are far more entertainment than science. There are so many unset variables in the basic idea that a generic question is meaningless for scientific purposes. It's like asking if Mighty Mouse could beat up Superman.

Well, less scientific, really, since Mighty Mouse is clearly stronger.

 

[Throckmorton]

Originally posted by: NanoStuff

Originally posted by: JujuFish
I can't believe this argument is still going on. The plane takes off.

Yes sir captain stupid.

The only way the plane wouldn't take off would be if the brakes were on.

 

[Fenixgoon]

interesting thing - i was telling my dad about this conundrum (he is also an aerospace engineer). the only thing that matters is plane speed WRT air, not the ground. the implications of this are interesting, even if they are not practical or possible.

let's say you had an aircraft carrier that could theoretically go 200+ mph - planes would automatically take off without ever needing a catapult because the plane's velocity WRT the air is the same as the speed of the carrier (200+mph, plenty fast for generating serious lift).
the same principle also applies to when test planes are launched midair from larger aircraft like B52's and 747's.

 

[Tweak155]

THIS IS FOR ALL THOSE THAT THINK THE AIRPLANE WILL NOT TAKE OFF (offering a different way to prove to yourself that you're wrong):

Lets say an airplane is flying and is about to land. It lands on this conveyor belt that is moving the opposite direction the plane is traveling.

Do you REALLY believe that it is physically possible for the airplane to land on this conveyor belt and all of a sudden sit still? This would require not moving forward an inch upon landing. I'll let you set the speed of the plane and the speed of the belt. If your numbers are outrageous, then I am allowed to insert that frictionless bearings and tire to conveyor belt friction is 0, which is also outrageous.

Car != airplane.

I realize this isn't the same scenario, but it helps illustrate that the airplane does not use the wheels/axles to move forward.

 

[mugs]

Originally posted by: Fenixgoon
interesting thing - i was telling my dad about this conundrum (he is also an aerospace engineer). the only thing that matters is plane speed WRT air, not the ground. the implications of this are interesting, even if they are not practical or possible.

let's say you had an aircraft carrier that could theoretically go 200+ mph - planes would automatically take off without ever needing a catapult because the plane's velocity WRT the air is the same as the speed of the carrier (200+mph, plenty fast for generating serious lift).
the same principle also applies to when test planes are launched midair from larger aircraft like B52's and 747's.

Yeah, that's a point I brought up in previous threads about this. Except my example was a big gust of wind (really really fast wind). Really it depends on the wording of the question - if the question asks "will the plane take off" it's not really kosher to add in a factor like that. If the question asks "can the plane take off" then it's OK. Everyone makes a big point about how it's the air moving over the wings that provides lift, not the thrust from the jet engines. If the plane doesn't move, there is no air moving over the wings. Even granting that the plane can't move (it can), the plane doesn't HAVE to move for air to move over its wings. Big gust of wind. Plane takes off.

The problem with this thread is that there IS no wording of the question in this thread. The thread was started by referencing the problem but not stating it. Thus everyone is arguing their own interpretation of the problem.

 

[JohnOfSheffield]

Originally posted by: DeathBUA
From Discovery Channel

Jamie and Adam take wing to test if a person with no flight training can safely land an airplane and if a plane can take off from a conveyor belt speeding in the opposite direction. Tory, Grant, and Kari jump on some Hollywood-inspired skydiving myths.


So despite being in TV guide and on discoverychannel.com that they would do plane on a conveyor belt discovery channel punk'd the entire internet, and especially ATOT since we have such hot debates about the plane on a conveyor. I must say I was highly disappointed.

Damn you discovery and damn you mythbusters!

If the conveyor belt is moving fast enough it will keep the plane in one place, no air passing the wings means no lifting power.

If you are not insane in the membrane you get this without a test.

Friction of wheels moving backwards at the same speed that the plane is propelled forwards means that the plane cannot move, it's as simple as shit and if you don't get it, you're retarded and i don't mean that in like "less knowledgeable" i really mean that you are fucked up in the skull in a way too serious to repair.

 

[Suspicious-Teach8788]

For everyone talking about the friction between the wheels and bearings, it's NEGLIGIBLE. This is one of those non-ideality factors that we can't really account for. Just like when we calculate free fall and we say that objects fall at the same speed etc etc, we pretty much ignore the concepts of air resistance and terminal velocity... then again we don't really calculate things that fall from 30,000 ft do we?

I think a lot of people are using terrible analogies here and it's confusing everyone. Free spinning wheels FTW.

Everyone who says no airmovement over wings = no lift so plane doesn't take off is correct in that no airflow = no lift, but the problem is that there IS airflow because the plane is moving WITH RESPECT TO THE GROUND. The treadmill matching the speed of the wheels is only supposed to throw you off. It has no effect whatsoever, and you merely think that it has an effect in terms of relative velocity when a treadmill is as good as any other runway.

 

[Dean]

Originally posted by: JohnOfSheffield

Originally posted by: DeathBUA
From Discovery Channel

Jamie and Adam take wing to test if a person with no flight training can safely land an airplane and if a plane can take off from a conveyor belt speeding in the opposite direction. Tory, Grant, and Kari jump on some Hollywood-inspired skydiving myths.


So despite being in TV guide and on discoverychannel.com that they would do plane on a conveyor belt discovery channel punk'd the entire internet, and especially ATOT since we have such hot debates about the plane on a conveyor. I must say I was highly disappointed.

Damn you discovery and damn you mythbusters!

If the conveyor belt is moving fast enough it will keep the plane in one place, no air passing the wings means no lifting power.

If you are not insane in the membrane you get this without a test.

Friction of wheels moving backwards at the same speed that the plane is propelled forwards means that the plane cannot move, it's as simple as shit and if you don't get it, you're retarded and i don't mean that in like "less knowledgeable" i really mean that you are fucked up in the skull in a way too serious to repair.

You are wrong!

There was another poster in this thread a few days ago that has an open door for you to walk through. It is to get your license. Yeah that's the ticket!!