Will the plane takeoff?

[PARAGON]

Originally Posted by NEOCON1

i want to see paragon hit the dash

I can accomodate very easily. It would be nothing to do it since you have all that hair to grab and smash your head into it with.

[paragoon]

It certainly won?t take off if I am driving it

[Wisha Haddan H3]

Originally Posted by NEOCON1

i want to see paragon hit the dash

I think he just hit my windshield and the wipers are smearing him around

[Wisha Haddan H3]

Originally Posted by PARAGON

The logic simply eludes you.

You are making an assumption to come to your conclusion. An assumption that is not offered by the question.

tracks the plane's speed

plane's speed relative to what? Relative to the conveyor? Airspeed, relative to the surrounding air?

The plane's speed relative to anything but the air is irrelevant to lift. The conveyor system can track whatever it wants and move the conveyor at any speed forward or backward. It wouldn't matter because the plane freewheels over its surface and propels itself by pushing static air.

If it's airspeed, the very point at which the plane breaks the hold (There is no hold - nothing attaches the plane to the conveyor) and theoretically begins to move, the conveyor would be moving it backwards (How? nothing attaches the plane to the conveyor) and the wheels would never rotate and the plane would remain stationary. (The wheels would roll but their rotation is irrelevant - they don't move or drive the plane) The plane is not being held stationary by any physical force, it's being held by the question. (False, the question does not create a scenario of zero velocity.) You have to assume that the plane starts to move and rotate the tires for the plane to gain airspeed. (Not so. the wheels are irrelevant except as a friction reducer between the plane and runway ... the same outcome would hold if it were a seaplane on pontoons over an ocean current, or on skis over a moving ice floe. Besides, if the conveyor followed the plane, the wheels wouldn't move either, but the plane would nonetheless move forward through the air, creating lift.) Well the question limits this assumption because one can make an assumption that allows for a different answer, therefore the question is flawed in that it allows for a yes and an no answer. (The assumption you say I "have to assume" is based on a false premise - the premise that the motion of a conveyor belt under a freewheeling air-powered vehicle can affect its linear motion)

If you can't see the simplicity of logic. I can't help further. (Right back at you, brother )

You have to go and make it "fit" into

One more analogy and I'm done ...

Imagine a moving sidewalk like those at the airport. If you walk in the direction of the movement, you travel at double your walking speed relative to the windows next to you. If you walk in the opposite direction, you remain stationary relative to the windows.

Why? Because the source of your motion is your feet pushing on the on the walkway thanks to friction.

Now, put on a pair of roller skates. I'll walk next to the moving sidewalk and pull you onto it with a rope. No matter what direction we take on the sidewalk, you will travel at the speed I'm walking. If we travel with the sidewalk, your wheels won't roll, because I'm walking as fast as the sidewalk. If we travel against it, the wheels will roll twice as fast as if I was pulling you over the carpet.

Why? Because the source of your motion is no longer your own feet "attached" to the conveyor through friction ... it comes from my feet exerting force on the stationary floor next to you while you freewheel on your skates.

Or if you like, I'll tie the rope to the wall and you can haul yourself up the rope towards me. The source of your motion is no longer me, it's you ... exerting force on the rope connected to the stationary wall. The moving sidewalk can speed up, slow down or stop, but it doesn't matter. Your motion relative to the windows next to you depends on your arms pulling the static medium of the rope tied to the wall while your skates freewheel below you.

Likewise, an airplane exerts its force directly on the static air around it ... not on the ground. The conveyor under the wheels can do what it wants (regardless of the sensors or relative speed) because the plane's engines are acting on the air while the tires freewheel below it. The plane's motion relative to the air around it depends on its engines pushing the wing through the static air, thus creating airflow and lift.

Consequently, the plane absolutely can take off within the parameters of this question as stated.

Have a nice day and thanks for the brainteaser. This was great!

[SnakeH2]

Originally Posted by H2Finally

A simple yes is wrong. Otherwise, airports will do away with long runways, and helicopters will be obsolete.

We need H2 GTS to chime in here...

Wrong. You're basing you assumption on the plane NOT moving.

[SnakeH2]

Originally Posted by H2Finally

A simple yes is wrong. Otherwise, airports will do away with long runways, and helicopters will be obsolete.

We need H2 GTS to chime in here...

Ahh yeah...that makes sense.

[GLBLWARMR]

The answer all depends on whether or not I am on the plane. Because I will be pissed if I do not make my connecting flight.

[KenP]

Originally Posted by KenP

No. The plane is "standing".

Or:

No. The plane isn't moving.

You're stupid. It will take off.

All the conveyor will do is cause the wheels to spin wildly. Imagine a rocket on wheels on the same conveyor. That rocket is going to take off...with the wheels spinning off.

What the wheels and conveyor do is irrelavent as none of that provides any propulsion. The wheels lower friction and provide for braking.

Theoretically, the conveyor could be moving backwards at double the speed of the plane and it still wouldn't matter. That would only cause the wheels to spin even faster, but the plane will still be getting thrust, moving forward and generating lift.

[SnakeH2]

Originally Posted by KenP

You're stupid. It will take off.

Best arguement yet!!!

[PARAGON]

Originally Posted by KenP

You're stupid. It will take off.

All the conveyor will do is cause the wheels to spin wildly. Imagine a rocket on wheels on the same conveyor. That rocket is going to take off...with the wheels spinning off.

What the wheels and conveyor do is irrelavent as none of that provides any propulsion. The wheels lower friction and provide for braking.

Theoretically, the conveyor could be moving backwards at double the speed of the plane and it still wouldn't matter. That would only cause the wheels to spin even faster, but the plane will still be getting thrust, moving forward and generating lift.

That's not true. Newton's law of motion states that the rocket or plane wants to stay still. As power is applied, as soon as it wants to start to roll, the conveyor moves, sending the motion back to a zero point.

That's where the conundrum lies with this version of the question. The plane can really never get up to any speed because it can't get past zero simply due to the limitations of the question IF you make certain assumptions OR it will take off IF you make other assumptions.

If the speed of the plane will always be instantaneously matched, the forward movement of the plane will never increase relative to it's surroundings.

If the plane starts to move at x MPH and instaneously the belt moves it -X MPH, the body of the plane remains still and actually does not move from a math standpoint.

But, assuming it's not a fictional question and the plane can move past this fictional "barrier of movement" then, as the plane increases it's speed, the plane is moving through the air and the belt is moving beneath and theoretically moving the wheels twice as fast.


That's why there were apparently different versions of the question. The one here was too vague and allowed for the No answer to be argued. The ones Bluehummer posted, that said speed relative to the wheels, changes the whole argument and allows the "body" of the plane to move without respect to the wheels.

[KenP]

I didn't look at his links () so I can't speak for that.

I do know that if I take a bottle rocket and attach it to a Matchbox on a beltsander spinning at full speed, light the rocket, it's going to go. Unless I accidentally sand my fingertips off.

I got my answer by cheating and reading a physics site. No, I didn't read all 15 pages!!!! Just the first and last few.

BTW, when I'm driving down the road and a fly is in the car, why doesn't the fly it the dash when I hit the brakes. And if the fly is flying around from front to back while I'm driving 55, what's the fly's speed in each direction?

[shakazulu12]

Ok I'm getting dizzy reading all these posts, but for those that say it won't take off, you are right.

Planes need forward movement through the air in order to generate negative pressure above the wing surface, thus creating lift. If the wing isn't moving through the air, then it doesn't matter what you do, it won't take off.

I think someone else already explained this, but this is the dumbed down version.

[PARAGON]

Originally Posted by KenP

I didn't look at his links () so I can't speak for that.

I do know that if I take a bottle rocket and attach it to a Matchbox on a beltsander spinning at full speed, light the rocket, it's going to go. Unless I accidentally sand my fingertips off.

I got my answer by cheating and reading a physics site. No, I didn't read all 15 pages!!!! Just the first and last few.

BTW, when I'm driving down the road and a fly is in the car, why doesn't the fly it the dash when I hit the brakes. And if the fly is flying around from front to back while I'm driving 55, what's the fly's speed in each direction?

speed relative to what?

he's basically hovering in the car since the air in the car is "not moving"

the mass of the air and his mass is so small that he can accomodate the change in speed of the car because the "air" he's hovering in doesn't all go rushing to front.

Say, like if the car's interior was 1/4 full of water. All the water would rush to the front and a fish that was hovering in the water would go with it.

[KenP]

Would he smack the dash? I want to see something hit the dash.

[Dug]

I never opened this thread till today. Nice arguement by the way. I read 3/4 of the post and got tired. I really want to know the answer . My redneck guess would be No Fvcking Way! How the hell does a normal airplane take of with no wind for lift. If anyone can prove otherwise lets see it. Doug

[Wisha Haddan H3]

Originally Posted by Dug

I never opened this thread till today. Nice arguement by the way. I read 3/4 of the post and got tired. I really want to know the answer . My redneck guess would be No Fvcking Way! How the hell does a normal airplane take of with no wind for lift. If anyone can prove otherwise lets see it. Doug

Answer 2 questions and you'll have the answer to this riddle ...

1. How does an airplane take off on a normal runway?

An airplane uses jets or props to push against the air with enough force to accelerate. As the wings slice through the still air, relative airflow creates lift and the plane takes off.

2. Could a conveyor turning backwards under the wheels hold it back?

No ... since the airplane's landing gear rolls freely, the conveyor has nothing to push against and cannot cancel out the plane's forward motion. It would spin the wheels faster than usual but the plane would take off normally.

[Agriv8r]

WHO GIVES A SH!T

BUT THE ANSWWER IS NO, WHEELS ARE FOR LANDING, THRUST IS FOR MOVEMENT TO FORCE AIR OVER THE WINGS FOR LIFT. A BETTER WAY TO PICTURE IT IS TO HAVE THE SAME AIRPLANE ON AN AIRCRAFT CARRIER DOING 60KNOTS INTO A 60 KNOT HEADWIND.

SO NOW THE REAL QUESTION IS, WHO GIVES A SH!T

[DURAMAX TIM]

Originally Posted by KenP

You're stupid. It will take off.

All the conveyor will do is cause the wheels to spin wildly. Imagine a rocket on wheels on the same conveyor. That rocket is going to take off...with the wheels spinning off.

What the wheels and conveyor do is irrelavent as none of that provides any propulsion. The wheels lower friction and provide for braking.

Theoretically, the conveyor could be moving backwards at double the speed of the plane and it still wouldn't matter. That would only cause the wheels to spin even faster, but the plane will still be getting thrust, moving forward and generating lift.

same as a float plane or plane w/ skis, wheels don't have to roll to take off.

[ROX]

Originally Posted by H2 rocks me

A plane is standing on a runway that can move (like a giant conveyor
belt). This conveyor has a control system that tracks the plane's
speed and tunes the speed of the conveyor to be exactly the same (but
in the opposite direction) instantly.

Will the plane be able to take off?

Yes, but only if you add enough Tequilla.

[CO Hummer]

Originally Posted by Wisha Haddan H3

Answer 2 questions and you'll have the answer to this riddle ...

1. How does an airplane take off on a normal runway?

An airplane uses jets or props to push against the air with enough force to accelerate. As the wings slice through the still air, relative airflow creates lift and the plane takes off.

2. Could a conveyor turning backwards under the wheels hold it back?

No ... since the airplane's landing gear rolls freely, the conveyor has nothing to push against and cannot cancel out the plane's forward motion. It would spin the wheels faster than usual but the plane would take off normally.

I see your point now. I agree!