Plane

[Voyager EMH]

More hot breaking news.

The new runway at Heathrow is going to be a conveyor belt.
It will be for landings only. Initially running at 100mph when planes land on it. It can then be considerably shorter than conventional runways.

It was considered that planes taking off on the conveyor running forwards might make takeoffs shorter as well. But this has been ruled out by a small group of experts.

 

[RichA]

Because time and time again you make the error of assuming the plane and car behave in a similar fashion.
You understood how it worked once, nothing has changed.

You cannot ignore the lews of motion , where is the force required to slow the planes acceleration coming from?

It's not the belt, thats just acting against the wheels and they are just free spinning so can't act against the thrust .
So where is that thrust going?

I don't.
I didn't, then I thought I did but was wrong, but now I do.
I'm not. Do you understand how a Catherine Wheel functions?
The thrust is forced around a pivot that is the stationary front wheels. The plane tips forward when the thrust overcomes the weight of its rear end. The Earth prevents further rotation.
It's not a real word scenario. In reality the thrust would overcome the unmoving wheel and push it forward, skidding until the tyres exploded.

 

[Deleted member 35927]

I don't.
I didn't, then I thought I did but was wrong, but now I do.
I'm not. Do you understand how a Catherine Wheel functions?
The thrust is forced around a pivot that is the stationary front wheels. The plane tips forward when the thrust overcomes the weight of its rear end. The Earth prevents further rotation.
It's not a real word scenario. In reality the thrust would overcome the unmoving wheel and push it forward, skidding until the tyres exploded.

Catherine wheels ? Wtf youre now using a wheels with it's own power source as an example. Jeez

 

[RichA]

Catherine wheels ? Wtf youre now using a wheels with it's own power source as an example. Jeez

You don't know what a Catherine Wheel is?
Rocket fireworks on sticks that rotate around a pivot. Take one of the fireworks and fix its stick to the ground with a hinge that allows it to rotate. Light the firework and see how far it gets.

 

[Deleted member 35927]

You don't know what a Catherine Wheel is?
Rocket fireworks on sticks that rotate around a pivot. Take one of the fireworks and fix its stick to the ground with a hinge that allows it to rotate. Light the firework and see how far it gets.

Yes I have no idea why you are talking about them just when I thought things couldn't get any more bizarre

 

[Voyager EMH]

Wow, the news is developing at a very fast rate.
Trump wants to be involved in the short conveyor belt runway at Heathrow.

When asked how it would work he replied, "Well if the plane is coming in at 150mph, we just have to have the conveyor running at 150mph in the opposite direction and the plane will come to a halt real quick. We need to look at a few things like making sure the wheels can grip the surface of the conveyor - we can't have the plane skidding along like its on ice. But plane going at 150mph and conveyor going at 150 mph in the opposite direction - ain't it obvious these will cancel each other out - the plane's gonna stop - like I said - real quick. I know there are some people who say it ain't gonna work, but for every one of them I can give you another 10 that will say it will work. Some said I couldn't become President a second time, but I have become President again. Some said I couldn't bring peace in the Middle East, but I am bringing peace in the Middle East. What I'm sayin' is, don't put money on this runway not working. Me and Elon are gonna be on Airforce1 for the first landing on that runway. Then we will see."

We asked the man from Hamburg who has been leading the group of experts from day one, whether he would be present at the momentumous inaugural landing.
(do you like my new made-up word?)
He replied, "Maybe, but I might be at the Bookie's with a large empty suitcase, waiting for my winnings."

 

[Swango1980]

You don't know what a Catherine Wheel is?
Rocket fireworks on sticks that rotate around a pivot. Take one of the fireworks and fix its stick to the ground with a hinge that allows it to rotate. Light the firework and see how far it gets.

Are we just naming different types of wheels now? I'll go with Steering Wheel

Or are we trying to define what a wheel is? We are really having to go back to first principles here

 

[SocketRocket]

The ground is hard and I landed funny.

I think you know what my question was targeted at

 

[RichA]

Are we just naming different types of wheels now? I'll go with Steering Wheel

Or are we trying to define what a wheel is? We are really having to go back to first principles here

No. Just thinking how I'd explain the theoretical but highly implausible scenario to an 8-year old, where a conveyor belt perfectly opposes all rotation of a plane's wheels.

Engine thrust is a vector force parallel to the ground.
If the wheels roll then the belt counteracts them. It's arguable that this prevents the wheels from ever actually turning at all, but if they do then the belt prevents any forward motion of the plane.
As the thrust overcomes the weight of the plane the force has to go somewhere, so the front wheels become a pivot for a rotational force and the plane tips forwards.

This assumes that the wheels are not allowed to skid in the made up scenario.
If the wheels can skid then the plane moves forwards. The wheels spin at the same rate the conveyor is moving, be that zero or whatever, and the plane might take off, if the friction doesn't destroy the tyres.

You guys spent 2 days trying to convince everyone you knew the answer and it was easy.
You suggested people should think about it with an open mind. A few have done so and figured stuff out.
Since then you changed your own explanations of the situation but carry on with the condescending remarks. It's not a great look.
Your most recent responses to suggested solutions give the impression you're copying them from an imperfect AI engine and have minimal understanding of the mechanics yourselves.

 

[Deleted member 35927]

No. Just thinking how I'd explain the theoretical but highly implausible scenario to an 8-year old, where a conveyor belt perfectly opposes all rotation of a plane's wheels.

Engine thrust is a vector force parallel to the ground.
If the wheels roll then the belt counteracts them. It's arguable that this prevents the wheels from ever actually turning at all, but if they do then the belt prevents any forward motion of the plane.
As the thrust overcomes the weight of the plane the force has to go somewhere, so the front wheels become a pivot for a rotational force and the plane tips forwards.

This assumes that the wheels are not allowed to skid in the made up scenario.
If the wheels can skid then the plane moves forwards. The wheels spin at the same rate the conveyor is moving, be that zero or whatever, and the plane might take off, if the friction doesn't destroy the tyres.

You guys spent 2 days trying to convince everyone you knew the answer and it was easy.
You suggested people should think about it with an open mind. A few have done so and figured stuff out.
Since then you changed your own explanations of the situation but carry on with the condescending remarks. It's not a great look.
Your most recent responses to suggested solutions give the impression you're copying them from an imperfect AI engine and have minimal understanding of the mechanics yourselves.

Nothings changed , plane takes off wether the belt is running towards or away from plane .
your explanation requires the use of magic

 

[Swango1980]

No. Just thinking how I'd explain the theoretical but highly implausible scenario to an 8-year old, where a conveyor belt perfectly opposes all rotation of a plane's wheels.

Engine thrust is a vector force parallel to the ground.
If the wheels roll then the belt counteracts them. It's arguable that this prevents the wheels from ever actually turning at all, but if they do then the belt prevents any forward motion of the plane.
As the thrust overcomes the weight of the plane the force has to go somewhere, so the front wheels become a pivot for a rotational force and the plane tips forwards.

This assumes that the wheels are not allowed to skid in the made up scenario.
If the wheels can skid then the plane moves forwards. The wheels spin at the same rate the conveyor is moving, be that zero or whatever, and the plane might take off, if the friction doesn't destroy the tyres.

You guys spent 2 days trying to convince everyone you knew the answer and it was easy.
You suggested people should think about it with an open mind. A few have done so and figured stuff out.
Since then you changed your own explanations of the situation but carry on with the condescending remarks. It's not a great look.
Your most recent responses to suggested solutions give the impression you're copying them from an imperfect AI engine and have minimal understanding of the mechanics yourselves.

Occasionally I made a light hearted remark, such as steering wheels. But, I hope I've not resorted to personal insults, like accusing someone of copying an AI Bot, or how someone spells their user name, etc. albeit it is sometimes tempting to give it back. And, maybe I do show my amazement at times that some actually believe a treadmill does have the force to stop a jet engine from propelling a plane forwards. I suspect some might have other motivations to prolong the debate, others find it an interesting teaser. In fairness, I didn't believe there was any general malice in our back and forths.

My stance has been consistent, but over this many pages of discussion, of course the flow of the discussion meanders. I have always said the plane takes off if it tries to as per normal (engines) and the treadmill will not stop that (if it is long enough). I've never seen this before, as I don't go on any other forums. So, the very first instant I saw it, I immediately told myself (the plane can't take off as it would be stationary on a treadmill). Before I typed a response, I quickly realized that this would be impossible, a treadmill offers no resistance to the thrust of a planes engines, which generates the force through the air, not through the ground. It isn't a car. It isn't a person running on a treadmill.

By the time I initially got involved, I had already seen several posters seemed to be insisting the planes engines were engaged but the treadmill was able to counter this. So, this was the "thrust" of my argument. As the question was "will the plane take off", my answer has always been yes.

However, had the meme ended "the plane takes off, can this be logically true?" then I would have spent more time evaluating the middle part of the meme. Can those words be logically true and the flight still take off? If the treadmill was operating backwards in relation to the flight, then no. But, of course if it was operating forwards, then yes. I noticed this when Crow first pointed it out, and it best fits the OP. Plane still takes off normally, so the words in the meme are consistent. The middle bit can be explained, rather than it being a paradox. I'm quite sure this was part of our discussion a good bit before you claimed I had suddenly changed my mind, and I certainly mentioned it to another forumer beforehand.

Perhaps "we" have spent 2 days discussing it, but you are included in the same boat. We've all been contributing to the thread, one way or another. I even noticed today that the Mythbusters actually did do the experiment very similar to the scenario many have discussed (plane taking off on a treadmill operating the same speed against the direction of the flight). Perhaps it has already been posted in here, but there are that many pages I'm not going back to check. And, the flight took off as normal, as I would expect.

My lighthearted reaction to Catherine Wheels wasn't a sly dig. It is just that my brain has fried after talking about wheels for 2 days, I think seeing or hearing about any type of wheel for the next few weeks might make me ill

 

[RichA]

Nothings changed , plane takes off wether the belt is running towards or away from plane .
your explanation requires the use of magic

No. Just an open mind, a bit of thought and the realisation that if the conundrum was to have a one word answer it would be torque.

 

[Tashyboy]

When a thread like this has more “ contributions “ than a mental health thread on the same forum. There’s something wrong.
That said. Would the same logic be applied to a biplane or the bloody red barons triplane.

 

[Swango1980]

When a thread like this has more “ contributions “ than a mental health thread on the same forum. There’s something wrong.
That said. Would the same logic be applied to a biplane or the bloody red barons triplane.

Don't worry. I think a thread like this will result in more contributions on the Mental Health thread, just to detox

 

[Voyager EMH]

Some have called it physics, but I have come at it as an applied maths question.
From 6th form to end of university something like this would be talked about and worked on for several hours of several days by students and tutors/lecturers.
The amount of time, the number of posts and the number of people involved on this forum has seemed fairly small-scale to me.
I've really enjoyed this thread.
For me it has been as much about "how the mind works - perception" as it is about the right and wrong answers to how a plane behaves on a conveyor.
The "how the mind works" is far more interesting to me than the right and wrong answers which are fairly humdrum in comparison.
Now then, that last sentence looks like a massive boast, "I'm better than all of you" sort of thing. I don't mean to be so boastful or condescending. I've merely been very interested in this type of thing for a very long time. And I can't really apologise for that. I'm interested in the subject matter, but just as interested in the perceptions and reasoning of all the other contributors. Thank you all.
Everyone coming to the same conclusion very quickly would be comparatively boring and uninteresting. This has been very interesting.
Me

 

[SteveW86]

Some have called it physics, but I have come at it as an applied maths question.
From 6th form to end of university something like this would be talked about and worked on for several hours of several days by students and tutors/lecturers.
The amount of time, the number of posts and the number of people involved on this forum has seemed fairly small-scale to me.
I've really enjoyed this thread.
For me it has been as much about "how the mind works - perception" as it is about the right and wrong answers to how a plane behaves on a conveyor.
The "how the mind works" is far more interesting to me than the right and wrong answers which are fairly humdrum in comparison.
Now then, that last sentence looks like a massive boast, "I'm better than all of you" sort of thing. I don't mean to be so boastful or condescending. I've merely been very interested in this type of thing for a very long time. And I can't really apologise for that. I'm interested in the subject matter, but just as interested in the perceptions and reasoning of all the other contributors. Thank you all.
Everyone coming to the same conclusion very quickly would be comparatively boring and uninteresting. This has been very interesting.
Me

I don’t think you ever need to worry about everyone on this forum coming to the same conclusion over anything,ever!

 

[Deleted member 35927]

No. Just an open mind, a bit of thought and the realisation that if the conundrum was to have a one word answer it would be torque.

I admire your perseverance, for me the one word answer is yes.

 

[Fade and Die]

No. Just thinking how I'd explain the theoretical but highly implausible scenario to an 8-year old, where a conveyor belt perfectly opposes all rotation of a plane's wheels.

Engine thrust is a vector force parallel to the ground.
If the wheels roll then the belt counteracts them. It's arguable that this prevents the wheels from ever actually turning at all, but if they do then the belt prevents any forward motion of the plane.
As the thrust overcomes the weight of the plane the force has to go somewhere, so the front wheels become a pivot for a rotational force and the plane tips forwards.

This assumes that the wheels are not allowed to skid in the made up scenario.
If the wheels can skid then the plane moves forwards. The wheels spin at the same rate the conveyor is moving, be that zero or whatever, and the plane might take off, if the friction doesn't destroy the tyres.

You guys spent 2 days trying to convince everyone you knew the answer and it was easy.
You suggested people should think about it with an open mind. A few have done so and figured stuff out.
Since then you changed your own explanations of the situation but carry on with the condescending remarks. It's not a great look.
Your most recent responses to suggested solutions give the impression you're copying them from an imperfect AI engine and have minimal understanding of the mechanics yourselves.

It reminds me of the saying about playing chess with a pigeon.

 

[RichA]

It reminds me of the saying about playing chess with a pigeon.

Never heard of it. Looked it up. Like it.

 

[sunshine]

Bit like a rolling road. When power testing my car it was "travelling" at 155mph on the rolling road without actually moving anywhere. But the power to move it at 155mph was still being generated.

Was cacking my pants that the rollers didn't fail!

ok, but did your car take off or not?