Brain Teaser - Will it take off??
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From: North of Dallas, South of Frisco
Exactly- The airplane will not fly.
It's engine will roar, there will be plenty of negated thrust- but with the conveyer belt negating the wheels- thus the airplane's forward momentum, the plane will sit in one spot with it's twin Pratt & Whitney F-100 turbofans on full afterburner, (Or Rolls Royce Merlin- which ever you prefer) never gaining speed, thus the wings never creating lift by wind moving under and over it's surface...
The only thing that could lift off under those conditions are:
AV-8
AV-8B
F-35 JSF
Helicopter
It's engine will roar, there will be plenty of negated thrust- but with the conveyer belt negating the wheels- thus the airplane's forward momentum, the plane will sit in one spot with it's twin Pratt & Whitney F-100 turbofans on full afterburner, (Or Rolls Royce Merlin- which ever you prefer) never gaining speed, thus the wings never creating lift by wind moving under and over it's surface...
The only thing that could lift off under those conditions are:
AV-8
AV-8B
F-35 JSF
Helicopter
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Originally Posted by Bighersh
Exactly- The airplane will not fly.
It's engine will roar, there will be plenty of negated thrust- but with the conveyer belt negating the wheels- thus the airplane's forward momentum, the plane will sit in one spot with it's twin Pratt & Whitney F-100 turbofans on full afterburner, (Or Rolls Royce Merlin- which ever you prefer) never gaining speed, thus the wings never creating lift by wind moving under and over it's surface...
The only thing that could lift off under those conditions are:
AV-8
AV-8B
F-35 JSF
Helicopter
It's engine will roar, there will be plenty of negated thrust- but with the conveyer belt negating the wheels- thus the airplane's forward momentum, the plane will sit in one spot with it's twin Pratt & Whitney F-100 turbofans on full afterburner, (Or Rolls Royce Merlin- which ever you prefer) never gaining speed, thus the wings never creating lift by wind moving under and over it's surface...
The only thing that could lift off under those conditions are:
AV-8
AV-8B
F-35 JSF
Helicopter
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From: SW MO
Originally Posted by rutherk1
You keep talking about relation but you are not getting the relation. The relation of the wheel speed when compared to the plane speed is 0.
Maybe it will be easier to understand if you take a car going 100 MPH. Take a gaint treadmill going 100 MPH the other direction and stick the car on top of it. The car would now be going 0 MPH.
Take a small plane going 100 MPH (already in the air) stick a treadmill spinning at the equivalent of 100MPH under the wheels. All the treadmill would do is make the wheels spin the in the opposite direction. The plane would still be going 100 MPH.
The plane will absolutely take off. Lift is acheived with the propellor. Not the wheels.
"Imagine you're wearing a jetpack and you are also running on the treadmill... all is fine
Now bend over to get the right thrust vector and light it up.. the rocket pack will push against the static air and shove you right off the front of the treadmill."
Maybe it will be easier to understand if you take a car going 100 MPH. Take a gaint treadmill going 100 MPH the other direction and stick the car on top of it. The car would now be going 0 MPH.
Take a small plane going 100 MPH (already in the air) stick a treadmill spinning at the equivalent of 100MPH under the wheels. All the treadmill would do is make the wheels spin the in the opposite direction. The plane would still be going 100 MPH.
The plane will absolutely take off. Lift is acheived with the propellor. Not the wheels.
"Imagine you're wearing a jetpack and you are also running on the treadmill... all is fine
Now bend over to get the right thrust vector and light it up.. the rocket pack will push against the static air and shove you right off the front of the treadmill."
You MUST define a constant. and yes I said we can "assume" the plane would lift, but there was too much info missing...
As for the rocket pack, if you hold on, you'll just push air, similar to a car on a dyno... or rocket booster on a test pad...
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From: The Internet
I think a light bulb just came on for me about this.
Let me ask this question. If a radar gun were pointed at the airplane just before it left the ground, it would read 140 mph or so, right? And not 0 mph?
Let me ask this question. If a radar gun were pointed at the airplane just before it left the ground, it would read 140 mph or so, right? And not 0 mph?
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From: SW MO
Originally Posted by rutherk1
It completely not the most important factor. The only factor in this is overcomming the EXTREREMLY slight amount of friction created in spinning the airplanes wheels backwards AS the propeller pushes through the static air.
The wind speed in not mentioned so its implied as being normal. Sure, if the windspeed was 100 MPH in the nose, the plane would have a hard time. That is not a factor in the brain teaser.
WHY IS THIS SO HARD FOR PEOPLE TO UNDERSTAND?!?!?
The wind speed in not mentioned so its implied as being normal. Sure, if the windspeed was 100 MPH in the nose, the plane would have a hard time. That is not a factor in the brain teaser.
WHY IS THIS SO HARD FOR PEOPLE TO UNDERSTAND?!?!?
You can't just assume anything...
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Originally Posted by closer9
If you'll look up a few post I too said the plane would lift. I never said it wouldn't, and no the car would not necessarily be going 0 mph on a giant treadmill. The speedo would be reading 100 mph, but what are you relating the motion of the car to? in relation to the treadmill the car is going 0, but in relation to the belt it's going 100 mph...
You MUST define a constant. and yes I said we can "assume" the plane would lift, but there was too much info missing...
As for the rocket pack, if you hold on, you'll just push air, similar to a car on a dyno... or rocket booster on a test pad...
You MUST define a constant. and yes I said we can "assume" the plane would lift, but there was too much info missing...
As for the rocket pack, if you hold on, you'll just push air, similar to a car on a dyno... or rocket booster on a test pad...
The wheel speed (until take off) is a result of the propeller making the plane move. If the wheels are being turned -100 MPH as the plane is taking off at 100 MPH then the wheels will just not be turning as the plane pulls it self with the prop.
Last edited by rutherk1; Dec 1, 2005 at 01:29 PM.
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From: SW MO
Originally Posted by Net Wurker
I think a light bulb just came on for me about this.
Let me ask this question. If a radar gun were pointed at the airplane just before it left the ground, it would read 140 mph or so, right? And not 0 mph?
Let me ask this question. If a radar gun were pointed at the airplane just before it left the ground, it would read 140 mph or so, right? And not 0 mph?
This is again relation. If the rador gun operator were standing on the ground (Earth) it would be one thing, if he were on the conveyor it would be something different, and if he were in the plane it would be 0.
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From: Edgewood TX
Net Wurker,
Yes, that's right.. the radar gun dosen't measure the speed of the spinning wheels, but rather the forward velocity of the airframe. if there were a 100 mph tailwind and the plane's takeoff speed was 140 mph, then the craft would have to be moving at 240mph (static) to overcome the tail wind and lift off.
Yes, that's right.. the radar gun dosen't measure the speed of the spinning wheels, but rather the forward velocity of the airframe. if there were a 100 mph tailwind and the plane's takeoff speed was 140 mph, then the craft would have to be moving at 240mph (static) to overcome the tail wind and lift off.
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From: SW MO
Originally Posted by rutherk1
Of course if you hold on you will not move. This can hardly imagine that this plane scenario takes into account that its BOLTED to the treadmill. But the fact that the plane would have to put forth no effort in order to keep it stationary further proves that the wheel speed has nothing to do with the plane taking off because the are free spinning.
I think we're both on the same page, maybe even the same conveyor. I just don't like to assume anything, and you are... that's all I'm saying...
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Originally Posted by Caseyh46
Net Wurker,
Yes, that's right.. the radar gun dosen't measure the speed of the spinning wheels, but rather the forward velocity of the airframe. if there were a 100 mph tailwind and the plane's takeoff speed was 140 mph, then the craft would have to be moving at 240mph (static) to overcome the tail wind and lift off.
Yes, that's right.. the radar gun dosen't measure the speed of the spinning wheels, but rather the forward velocity of the airframe. if there were a 100 mph tailwind and the plane's takeoff speed was 140 mph, then the craft would have to be moving at 240mph (static) to overcome the tail wind and lift off.
Put a car on skies and have it drive through the snow.
No go.
This treadmill question only applies to vehicles that are powered by putting force to the ground.
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I see the light now. If the wheels were what actually propelled the airplane forward (like they do a car), then the airpalne would be sitting stationary on the conveyor. But since they just free-wheel, and the prop is what causes the forward motion of the airplane, then it actually starts to move forward. Since the airplane is actualy moving forward, then lift is created.
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Originally Posted by Net Wurker
I see the light now. If the wheels wee what actually propelled the airplane forward (like they do a car), then the airpalne would be sitting stationary on the conveyor. But since they just free-wheel, and the prop is what causes the forward motion of the airplane, then it actually starts to move forward. Since the airplane is actualy moving forward, then lift is created.
THANK YOU!
Someone actually read some of the posts that explain WHY THE PLANE WILL FLY!!
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From: Olympia, WA
Gotta love this thread. Now what type of oil is the plane using - dino or synthethic - and how often does the pilot change it? 
To anyone who doubts the plane will take off - explain to me how the wheels of an airplane have any effect on its performance other than steering?
It has been stated MANY times in this thread that the thrust produced by the props or jet engines relative to the air around the plane is what creates forward momentum - not the wheels. Unless the conveyor is producing a hell of a tail wind, the plane will take off just like it would w/o being on a conveyor.
The wheels on an airplane in this example are about as important (or unimportant) as ambient wind to a car on a dyno. The car doesn't know or care whether the wind is blowing or in which direction. The car's wheels produce thrust relative to the dyno's rollers. The plane's engines produce thrust relaive to the air.
Now, isn't there a booty thread or something we can all agree on?
To anyone who doubts the plane will take off - explain to me how the wheels of an airplane have any effect on its performance other than steering?
It has been stated MANY times in this thread that the thrust produced by the props or jet engines relative to the air around the plane is what creates forward momentum - not the wheels. Unless the conveyor is producing a hell of a tail wind, the plane will take off just like it would w/o being on a conveyor.
The wheels on an airplane in this example are about as important (or unimportant) as ambient wind to a car on a dyno. The car doesn't know or care whether the wind is blowing or in which direction. The car's wheels produce thrust relative to the dyno's rollers. The plane's engines produce thrust relaive to the air.
Now, isn't there a booty thread or something we can all agree on?
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From: Pikesville, MD
Originally Posted by rutherk1
DING DING DING DING !!!!!
THANK YOU!
Someone actually read some of the posts that explain WHY THE PLANE WILL FLY!!
THANK YOU!
Someone actually read some of the posts that explain WHY THE PLANE WILL FLY!!
And what happens if you turn off the conveyor belt right before lift off?
and are they serving peanuts or pretzels...some people have alergies you know.
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Originally Posted by Fritz_H
Gotta love this thread. Now what type of oil is the plane using - dino or synthethic - and how often does the pilot change it?
To anyone who doubts the plane will take off - explain to me how the wheels of an airplane have any effect on its performance other than steering?
It has been stated MANY times in this thread that the thrust produced by the props or jet engines relative to the air around the plane is what creates forward momentum - not the wheels. Unless the conveyor is producing a hell of a tail wind, the plane will take off just like it would w/o being on a conveyor.
The wheels on an airplane in this example are about as important (or unimportant) as ambient wind to a car on a dyno. The car doesn't know or care whether the wind is blowing or in which direction. The car's wheels produce thrust relative to the dyno's rollers. The plane's engines produce thrust relaive to the air.
Now, isn't there a booty thread or something we can all agree on?
To anyone who doubts the plane will take off - explain to me how the wheels of an airplane have any effect on its performance other than steering?
It has been stated MANY times in this thread that the thrust produced by the props or jet engines relative to the air around the plane is what creates forward momentum - not the wheels. Unless the conveyor is producing a hell of a tail wind, the plane will take off just like it would w/o being on a conveyor.
The wheels on an airplane in this example are about as important (or unimportant) as ambient wind to a car on a dyno. The car doesn't know or care whether the wind is blowing or in which direction. The car's wheels produce thrust relative to the dyno's rollers. The plane's engines produce thrust relaive to the air.
Now, isn't there a booty thread or something we can all agree on?