OT riddle. v. Plane vs. Treadmill

[JaSSon]

You're a fool to believe the plane would remain stationary. If the engines are pushing against the AIR, why would the plane remain stationary? The wheels are not locked or tied into any sort of transmission, and as such their rotation would have no effect on the thrust generated or on forward motion.

[RedRocket1647545505]

You're a fool to believe the plane would remain stationary. If the engines are pushing against the AIR, why would the plane remain stationary? The wheels are not locked or tied into any sort of transmission, and as such their rotation would have no effect on the thrust generated or on forward motion.

 

This goes back to the model car explaination. Given enough time, the plane could be pulled backwards on the treadmill at a high rate of speed. As Ken said, this is a HYPOTHETICAL situation.

[Sam1647545489]

That thread is like a 10 page thread on OT. There are a shit ton of people that say yes it will take off...

[Sam1647545489]

Some guy seems to think he has solved the riddle on OT

 

This is just to simplify, the truck pulling the plane will have the exact same effect as the jet engine propelling the plane, it's just easier to visualize this way. if the truck moves forward, pulling the plane, the plane will also move forward, regardless of the wheel speed.

 

Quote:

Originally Posted by netkilla

were did the truck come from. there was no truck in the original statement.. the plane also has no wheels. and does the truck have a cummings turbo diesel? THINK before you post

 

read what i posted, the truck is just an EXAMPLE, of external force not affected by the conveyor belt, the EXACT same kind of "external" force a jet engine supplies, as it is not affected by the conveyor belt, the truck is an EXAMPLE to make it simpler for those who do not understand.

 

 

another example:

 

a helicopter hovers over top of this conveyor belt, it has INDEPENDENT POWER from its spinning blades, just as a jet has independent power from jet engines, now if the helicopter moves forward hovering above the belt, it is going to move forward, yes?

 

say it is moving forward at 50 mph, just visualize it. the helicopter is moving forward at 50 mph right? now say the belt starts moving at 50mph, the helicopter will still move forward at 50mph right?

 

now say the helicopter has wheels inside, that lower themselves so they touch the belt. when those wheels are lowered , is the helicopter going to suddenly stop moving at 50mph in a forward direction? or is it going to keep going forward at 50mph, and the wheels will spin at 100mph. it is going to keep going forward ok?

 

now if the belt increases its speed to match the helicopters speed, it is only going to spin the wheels more.

 

 

keep in mind i am just unsing a helicopter as an example, it has external power sources, its wings, just as a plane has its jet engine, neither affected by the belt moving. if you cannot understand this, then i am sorry, believe what you want.

 

Quote:

Originally Posted by assclown

No it isn't. If the plane thrusts forward, say at 178mph or whatever and the conveyer belt is going in the opposite direction fast enough to keep the plane at a standstill relative to earth, there would still be no wind.

 

 

if the wheels were the only things on the belt............................

 

 

but it has a jet engine that is NOT affected by the belt pushing it forwards. so if the jet engine propelled it forward at 20 mph and the belt was going 50, the wheels would actually be going 70, if the belt went up to 80, the wheels would spin at 100, and the plane would still go forward at 20mph, it doesnt matter the speed of the belt.

 

 

now, disprove this my findings. you cannot.

[RedRocket1647545505]

That thread is like a 10 page thread on OT. There are a shit ton of people that say yes it will take off...

 

And there are a shit ton of dumb people in that 10 page thread.

 

The only way it could magically take off would be if it had an LSx motor in it. Other than that, it's staying on the ground.

[VDUB]

And....

 

the first rule of OT....

[Berto]

the treadmill moving will not keep the plane from moving, its a simple free body diagram the only thing keeping the plane from moving is the friction of the wheel bearings no which is negligible compared to the thrust provided by the engines. you can move that treadmill however fast you want (say the treadmill is as long as the runway) the wheels would be going twice as fast as whatever speed it needs to take off but it will still take off. the only way you would keep the plane from moving is to somehow resist the thrust.

[RedRocket1647545505]

the treadmill moving will not keep the plane from moving, its a simple free body diagram the only thing keeping the plane from moving is the friction of the wheel bearings no which is negligible compared to the thrust provided by the engines. you can move that treadmill however fast you want (say the treadmill is as long as the runway) the wheels would be going twice as fast as whatever speed it needs to take off but it will still take off. the only way you would keep the plane from moving is to somehow resist the thrust.

 

 

*sigh*....You people just don't get it.

 

Let's put it this way. Let's say that you start moving the treadmill in reverse at a slowly increasing speed. Now, you turn on the engines to provide just enough thrust to slow the planes rearward travel, bringing it's overall airspeed to 0. You continue doing this until the treadmill is going 11ty billion mph in reverse, and the plane is going 11ty billion mph forward. This still brings your airspeed to 0!!!.

 

I'm going back to my model car theory. Most you you nay sayers must also believe that a model car will stay in the same place indefinitely. I don't care how massive the plane is, it will eventually begin to move backwards, regardless of wheel spin.

 

 

I'm not saying that the plane is going to hammerdown on the throttle, outrun the treadmill and take off. I'm saying the two will be matching speeds. If it takes 30 years of accelerating to compensate for the ineria, then so be it.

[SPLN SUX]

*sigh*....You people just don't get it.

 

Let's put it this way. Let's say that you start moving the treadmill in reverse at a slowly increasing speed. Now, you turn on the engines to provide just enough thrust to slow the planes rearward travel, bringing it's overall airspeed to 0. You continue doing this until the treadmill is going 11ty billion mph in reverse, and the plane is going 11ty billion mph forward. This still brings your airspeed to 0!!!.

 

I'm going back to my model car theory. Most you you nay sayers must also believe that a model car will stay in the same place indefinitely. I don't care how massive the plane is, it will eventually begin to move backwards, regardless of wheel spin.

 

 

I'm not saying that the plane is going to hammerdown on the throttle, outrun the treadmill and take off. I'm saying the two will be matching speeds. If it takes 30 years of accelerating to compensate for the ineria, then so be it.

 

Ok 2 things.

 

1. Like i said last night/ early AM... thats not what the question asks.

 

2. For the love of god its I N E R T I A

[Mallard]

*sigh*....You people just don't get it.

 

Let's put it this way. Let's say that you start moving the treadmill in reverse at a slowly increasing speed. Now, you turn on the engines to provide just enough thrust to slow the planes rearward travel, bringing it's overall airspeed to 0. You continue doing this until the treadmill is going 11ty billion mph in reverse, and the plane is going 11ty billion mph forward. This still brings your airspeed to 0!!!.

 

I'm going back to my model car theory. Most you you nay sayers must also believe that a model car will stay in the same place indefinitely. I don't care how massive the plane is, it will eventually begin to move backwards, regardless of wheel spin.

 

 

I'm not saying that the plane is going to hammerdown on the throttle, outrun the treadmill and take off. I'm saying the two will be matching speeds. If it takes 30 years of accelerating to compensate for the ineria, then so be it.

No, I don't think you are getting it. *sigh*

 

Everything Sam and Berto have posted is correct. A jet engine produces thrust to push itself through the air. It doesn't matter how fast the gournd is moving because it's pulling itself through the air, it's not driving the wheels. The plane could possibly stay stationary of it were on a treadmill in an extremely high powered wind tunnel, but then you would have air velocity over the wings so it would take off. So maybe you could enclose just the engines in the wind tunnel and isolate the wings from the air in order to keep the plane on the ground.

 

Here's my analogy for ya: Go swim in a pool. Now imagine the floor of the pool is a treadmill. If you swim over the treadmill are you still going to move through the water? Of course you will because you're pulling through the water, and not using the ground for any of your driving force. The only difference between that and the plane is wheel bearing and ground friction, and water is a thicker fluid then air, but it's basically the same.

 

In short, if you could get the plane to somehow not move on the treadmill then no, the plane will not take off because lift is dependant on air speed over the wings. But the question is irrelivent because the plane will never stay on the treadmill in the first place.

[SPLN SUX]

ok... Alex got it in post #4... i sealed this thing in post #9.... why are we now approaching post 40???

 

Oh i know, because 1 person is answering a questin he read, while the others are answering what was typed. Yea thats why.

[Mallard]

I don't know what you think you "sealed" in post number nine since the question is about a jet engine and you say it's getting its forward motion from a prop. Although the end result remains the same, "sealed" usually means your arguement is completely watertight and accurate.

 

 

 

 

 

and yes, I just like ripping on everything you say.

[RedRocket1647545505]

No, I don't think you are getting it. *sigh*

 

Everything Sam and Berto have posted is correct. A jet engine produces thrust to push itself through the air. It doesn't matter how fast the gournd is moving because it's pulling itself through the air, it's not driving the wheels. The plane could possibly stay stationary of it were on a treadmill in an extremely high powered wind tunnel, but then you would have air velocity over the wings so it would take off. So maybe you could enclose just the engines in the wind tunnel and isolate the wings from the air in order to keep the plane on the ground.

 

Here's my analogy for ya: Go swim in a pool. Now imagine the floor of the pool is a treadmill. If you swim over the treadmill are you still going to move through the water? Of course you will because you're pulling through the water, and not using the ground for any of your driving force. The only difference between that and the plane is wheel bearing and ground friction, and water is a thicker fluid then air, but it's basically the same.

 

In short, if you could get the plane to somehow not move on the treadmill then no, the plane will not take off because lift is dependant on air speed over the wings. But the question is irrelivent because the plane will never stay on the treadmill in the first place.

 

 

Ok, so you're saying that the plane WILL NOT be pulled rearward, at all, by the treadmill?

 

Next. Your pool theory. You're saying to swim OVER the treadmill. In relation to your analogy, the plane isn't flying OVER the ground. The wheels are, in fact, touching the ground. If you're swimming over the treadmill and swim low enough so your stomach touches it, you will be pulled backwards, no matter how slight.

 

 

 

And Nick, you don't even want to get started on spelling errors... That is like the 3rd word I have ever spelled incorrectly on CR. Don't read too deep into that.

[Guest DagoRcR]

broke rule number 1

 

haha, jk

[Berto]

Phil, at least we know we are right, fuck em.

[Mallard]

Ok, so you're saying that the plane WILL NOT be pulled rearward, at all, by the treadmill?

Not if the engine is producing enough thrust to counteract the force in the treadmill exerts on the wheels, which for the amount of power a jet liner has would probably be a hair over idle.

 

Next. Your pool theory. You're saying to swim OVER the treadmill. In relation to your analogy, the plane isn't flying OVER the ground. The wheels are, in fact, touching the ground. If you're swimming over the treadmill and swim low enough so your stomach touches it, you will be pulled backwards, no matter how slight.

Yes if my stomach touches the treadmill I would be pulled backwards. But my stomach is not like the wheels of the plane. My stomach is rock hard and does not roll on bearings like the airplane's wheels do. If I were swimming, and had wheels attached to my body that rode on low friction bearings, then the speed of the tread mill would not keep me swimming in the same place. You would have to put me in a stream or river and have me swim against the current. They actually have pools that simulate this.

 

The pool analogy is applicable in this situation because the jet engine's thrust is much like a stroke in the pool. Neither the swimmer or the jet care how fast the ground is moving because their thrust relies on the fluid they operate within (air/water). The drag of the wheels on the ground is tiny in comparison to the thrust of the engine.

[Mallard]

Phil, at least we know we are right, fuck em.

engineers own

[iwishiwascool]

Of course the turbines would create enough thrust to overcome the ability of the treadmill to compensate. That isnt the question. Obviously if the plane begins to move forward at any point, it will eventually reach flight speed.

 

This is a fantasy situation involving a treadmill that can indeed match the potential forward momentum of the engines.

 

This is arguement of those who are looking at the black and white of the question, and those that are throwing in variables that arent introduced in the riddle.

[Mallard]

The riddle is a trick question and the number of idiots that populate the internet turn trick questions into 20 page posts arguing over their stupidity.

 

How much wood would a woodchuck chuck if a woodchuck could chuck wood? It's doesn't fucking matter because it's can't happen.