Airplane on a treadmill!

[Ichinisan]

Jesus fucking Christ. This has been done to death. The only explanation for why this discussion would still interest you:

1. You're an idiot, or...
2. You're a troll

Which is it?

Many people (including me) seem to think the best way to interpret the issue is that the treadmill is always going fast enough to prevent the plane from moving relative to the ground, thus keeping it from acquiring enough lift to take off.

*facepalm

 

[Ichinisan]

oh god not this again.

Can't believe it took 11 posts for someone to say what needed to be said.

 

[sdifox]

Decent point, but that is an empty 747 rather than a 747 that is loaded to normal takeoff levels.

I don't think a normally loaded 747 could take off if you added the weight and drag of a space shuttle to it.

EDIT: Maybe it could with a long enough runway?

Heavily reinforced 747-100. Pretty sure the reinforcement and shuttle weight more than passenger plus luggage.

 

[cbrunny]

Mythbusters did it. Plane takes off.

 

[flexy]

Jesus fucking Christ. This has been done to death. The only explanation for why this discussion would still interest you:

1. You're an idiot, or...
2. You're a troll

Which is it?



*facepalm

Yes, but is 0.999999999999(infinity) really 1?

 

[Zeze]

I'm still not convinced how the plane will take off. I've read bunch of stuff that it would because the velocity of the wheel doesn't matter.

But I can't picture it.

So the plane is literally sitting still, just the wheel spinning. Then once the plane start to lift off, is it going up vertically or at an angle? If at an angle, is it suddenly bursting into speed into the air? I don't see that happening physically.

Help me understand here. I had to do a motion with my hand being a plane and how it would nose up while being still. I don't get how it can take off.

Mythbusters did it. Plane takes off.

Link? I highly doubt whatever miniaturized test they did proves that a real 700,000 pound 747 taking off on an equally large theoretical treadmill.

https://www.youtube.com/watch?v=0KsdMuhYJPw

What the hell, the plane wasn't stationary.

 

[Bubbleawsome]

Jesus fucking Christ. This has been done to death. The only explanation for why this discussion would still interest you:

1. You're an idiot, or...
2. You're a troll

Which is it?



*facepalm

Hey I figured it out later in the thread. :awe:

Yes, but is 0.999999999999(infinity) really 1?

0.999...=x
9.999...=10x
9=9x
1=x

It's obvious :|
/s

 

[Tweak155]

I'm still not convinced how the plane will take off. I've read bunch of stuff that it would because the velocity of the wheel doesn't matter.

But I can't picture it.

So the plane is literally sitting still, just the wheel spinning. Then once the plane start to lift off, is it going up vertically or at an angle? If at an angle, is it suddenly bursting into speed into the air? I don't see that happening physically.

Help me understand here. I had to do a motion with my hand being a plane and how it would nose up while being still. I don't get how it can take off.



Link? I highly doubt whatever miniaturized test they did proves that a real 700,000 pound 747 taking off on an equally large theoretical treadmill.

You have a faulty assumption that the plane is sitting still. Assuming you're serious of course.

There is no force a treadmill could provide that would keep a plane still. All it could do is spin the wheels faster.

 

[waggy]

Take-off speed of an airplane is relative to the air, not the ground (or a treadmill).

it's amazing how many people have no idea how jet engines work either. the treadmill? who cares how fast it's going. its not going to keep the plane stationary.

but anyway. This topic has been debated on AT a ton. It's also been on mythbusters (the plane flew) and had actual scientist get on it and say it takes off.

sigh.

 

[sdifox]

I'm still not convinced how the plane will take off. I've read bunch of stuff that it would because the velocity of the wheel doesn't matter.

But I can't picture it.

So the plane is literally sitting still, just the wheel spinning. Then once the plane start to lift off, is it going up vertically or at an angle? If at an angle, is it suddenly bursting into speed into the air? I don't see that happening physically.

Help me understand here. I had to do a motion with my hand being a plane and how it would nose up while being still. I don't get how it can take off.



Link? I highly doubt whatever miniaturized test they did proves that a real 700,000 pound 747 taking off on an equally large theoretical treadmill.

https://www.youtube.com/watch?v=0KsdMuhYJPw

What the hell, the plane wasn't stationary.

grow up.

 

[Bubbleawsome]

I'm still not convinced how the plane will take off. I've read bunch of stuff that it would because the velocity of the wheel doesn't matter.

But I can't picture it.

So the plane is literally sitting still, just the wheel spinning. Then once the plane start to lift off, is it going up vertically or at an angle? If at an angle, is it suddenly bursting into speed into the air? I don't see that happening physically.

Help me understand here. I had to do a motion with my hand being a plane and how it would nose up while being still. I don't get how it can take off.



Link? I highly doubt whatever miniaturized test they did proves that a real 700,000 pound 747 taking off on an equally large theoretical treadmill.

The issue is that the treadmill can't keep the plane from moving. The engines don't apply thrust to the ground but into the air behind the plane. The treadmill isn't anchored to the 747 at all, the wheels spin freely. So as long as you can get over the miniscule resistance the wheel bearings have you can move forwards no matter what.

If the treadmill is moving backwards at 1000mph and the plane needs to move forwards at 150mph to take off the wheels may move at 1150mph (and explode) but the plane's thrust is applied to the air.

That's a bad explanation :$

 

[cbrunny]

What the hell, the plane wasn't stationary.

Yeah that's the point.

 

[Chiropteran]

What the hell, the plane wasn't stationary.

Call it a flaw in the original preposition if you want, but the fact is that a treadmill is incapable of keeping a plane stationary, regardless of how fast it moves. Not enough friction to overcome the force of thrust from the plane's engines.

 

[Zeze]

The issue is that the treadmill can't keep the plane from moving. The engines don't apply thrust to the ground but into the air behind the plane. The treadmill isn't anchored to the 747 at all, the wheels spin freely. So as long as you can get over the miniscule resistance the wheel bearings have you can move forwards no matter what.

If the treadmill is moving backwards at 1000mph and the plane needs to move forwards at 150mph to take off the wheels may move at 1150mph (and explode) but the plane's thrust is applied to the air.

That's a bad explanation :$

I understand it's the propeller taking in air and expelling it behind for thrust and how that enables flight. I also understand it has nothing to do with the wheels. I also understand wheels just spin around freely to whatever momentum the propeller & air provide.

But the mythbuster episode was faulty or inconclusive at best to the original proposal of the question.

The belt did NOT match the wheel's speed. It moved FORWARD (prior to takeoff) because the belt couldn't match it.

Let's suppose the plane's wheels were gear-shaped with teeth, and they were locked to the opposing teeth holes in the conveyor belt. Therefore we know 100% that plane couldn't move forward PRIOR to takeoff. If the plane nosed up and took off while remaining STATIONARY (which mythbuster truly failed at), then I'll believe it. Because THAT WAS THE PROPOSAL.

No I'm not trolling. I'd like to learn here and I think I presented valid points. Or at least, the Mythbusters failed at it.

 

[Zeze]

Call it a flaw in the original preposition if you want, but the fact is that a treadmill is incapable of keeping a plane stationary, regardless of how fast it moves. Not enough friction to overcome the force of thrust from the plane's engines.

I understand. Mythbusters' call it 'BUST' is definitely faulty, or at least premature. The original preposition was that the plane was supposed to remain stationary as the treadmill kept the forward motion in check.

 

[gorcorps]

isn't this a debate from a decade ago?

Did the OP just join the internet?

Also, with how many explanations there are of the correct answer by this point, how are so many people still getting this wrong?

conclusion: OP is just trolling

 

[Zeze]

isn't this a debate from a decade ago?

Did the OP just join the internet?

Also, with how many explanations there are of the correct answer by this point, how are so many people still getting this wrong?

conclusion: OP is just trolling

OP may be trolling, I'm not. I'm commenting directly on the Mythbuster video. I'm not sure if that was addressed on the old thread.

 

[disappoint]

I'm still not convinced how the plane will take off. I've read bunch of stuff that it would because the velocity of the wheel doesn't matter.

But I can't picture it.

So the plane is literally sitting still, just the wheel spinning. Then once the plane start to lift off, is it going up vertically or at an angle? If at an angle, is it suddenly bursting into speed into the air? I don't see that happening physically.

Help me understand here. I had to do a motion with my hand being a plane and how it would nose up while being still. I don't get how it can take off.



Link? I highly doubt whatever miniaturized test they did proves that a real 700,000 pound 747 taking off on an equally large theoretical treadmill.

https://www.youtube.com/watch?v=0KsdMuhYJPw

What the hell, the plane wasn't stationary.

Seriously? You still don't get it? The plane takes off because of thrust from the jet (or prop it wouldn't matter) engines. Edit: That causes it to move forward, the lift comes from air flow around the wings once it gets moving fast enough.

Having said that I have not seen the Mythbusters video and I don't really care to.

 

[waggy]

OP may be trolling, I'm not. I'm commenting directly on the Mythbuster video. I'm not sure if that was addressed on the old thread.

do a search on. there have been scientific types that explain in detail WHY the plane takes off. This was debated to death years ago.

NO MATTER what treadmill you put it on. The thrust from the engines are going to propel it foreword. basically the treadmill means jack shit.

 

[disappoint]

I understand. Mythbusters' call it 'BUST' is definitely faulty, or at least premature. The original preposition was that the plane was supposed to remain stationary as the treadmill kept the forward motion in check.

Why would the treadmill stop forward motion?

 

[Chiropteran]

If the plane nosed up and took off while remaining STATIONARY (which mythbuster truly failed at), then I'll believe it. Because THAT WAS THE PROPOSAL.[/B]

The key is in the wording of the question. The OP here didn't really word the question in the normal way, so google to the rescue!

Imagine a 747 is sitting on a conveyor belt, as wide and long as a runway. The conveyor belt is designed to exactly match the speed of the wheels, moving in the opposite direction. Can the plane take off?

Some people mistakenly assume that the conveyor belt will actually succeed in keeping the plane stationary. Really, that is the whole trick to the puzzle- a conveyor belt *can't* keep a plane stationary, period. It doesn't matter if it matches the speed of the wheels, the thrust of the plane doesn't care and is just going to keep applying force to pull the plane forwards.

 

[disappoint]

The key is in the wording of the question. The OP here didn't really word the question in the normal way, so google to the rescue!

Imagine a 747 is sitting on a conveyor belt, as wide and long as a runway. The conveyor belt is designed to exactly match the speed of the wheels, moving in the opposite direction. Can the plane take off?

Some people mistakenly assume that the conveyor belt will actually succeed in keeping the plane stationary. Really, that is the whole trick to the puzzle- a conveyor belt *can't* keep a plane stationary, period. It doesn't matter if it matches the speed of the wheels, the thrust of the plane doesn't care and is just going to keep applying force to pull the plane forwards.

Did you mean push the plane forward? Thrust is usually a push action. It would be the same if it was rocket propelled.

 

[Ichinisan]

I'm still not convinced how the plane will take off. I've read bunch of stuff that it would because the velocity of the wheel doesn't matter.

But I can't picture it.

So the plane is literally sitting still, just the wheel spinning. Then once the plane start to lift off, is it going up vertically or at an angle? If at an angle, is it suddenly bursting into speed into the air? I don't see that happening physically.

Help me understand here. I had to do a motion with my hand being a plane and how it would nose up while being still. I don't get how it can take off.



Link? I highly doubt whatever miniaturized test they did proves that a real 700,000 pound 747 taking off on an equally large theoretical treadmill.

https://www.youtube.com/watch?v=0KsdMuhYJPw

What the hell, the plane wasn't stationary.

The plane is not sitting still just because the treadmill matches its speed. The treadmill cannot make a plane sit still. If the treadmill matches the plane's speed, the plane is still moving forward at normal speed...but the tires are spinning at twice their normal speed. Relative to the ground, the plane moves just as far/fast as it normally would.

We're doing this again. FUCK.

 

[Chiropteran]

Did you mean push the plane forward? Thrust is usually a push action. It would be the same if it was rocket propelled.

Sure, you can call it a push if you want.

 

[Ichinisan]

I understand it's the propeller taking in air and expelling it behind for thrust and how that enables flight. I also understand it has nothing to do with the wheels. I also understand wheels just spin around freely to whatever momentum the propeller & air provide.

But the mythbuster episode was faulty or inconclusive at best to the original proposal of the question.

BASIC Newtonian physics. You push air one way, you go the other way.

The belt did NOT match the wheel's speed. It moved FORWARD (prior to takeoff) because the belt couldn't match it.

The treadmill could go 10x the speed of the plane. The plane moves forward and its tires just get spun faster. The speed of the treadmill makes no significant difference until it reaches the point that the bearings of the wheels fail and the wheels melt or disintegrate. Get it?

Let's suppose the plane's wheels were gear-shaped with teeth, and they were locked to the opposing teeth holes in the conveyor belt. Therefore we know 100% that plane couldn't move forward PRIOR to takeoff.

So the plane can't move forward just because the wheels are spinning really, really fast? No.

If the plane nosed up and took off while remaining STATIONARY (which mythbuster truly failed at), then I'll believe it. Because THAT WAS THE PROPOSAL.

Why would the plane be stationary? The treadmill acting only on the wheels could not make the plane remain stationary. It would just make the wheels spin real real fast. K?

No I'm not trolling.

Then you're in a club that contains a high percentage of idiots. Time to get a better understanding of this concept.

I'd like to learn here and I think I presented valid points.

No. Those "points" are 100% invalid.

Or at least, the Mythbusters failed at it.

Incorrect. You failed at understanding. How could you possibly even expect the plane to remain stationary with only a treadmill acting only on the wheels? HOW?!

The treadmill doesn't match the wheel speed. It matches the plane's speed. Wheels spin twice as fast as they normally would, but the plane moves forward at the same speed it would without a treadmill.

If you want the treadmill to match the wheel speed, everything (wheels and treadmill) disintegrates as soon as the plane starts moving forward.