Can a Plane on a Treadmill Take Off?

On Sat, 4 Feb 2006 08:44:24 -0800, "RST Engineering"
wrote:

Cecil Adams (world's smartest human being) is correct to a first
approximation. The correct answer to a second approximation is that it will
take off normally less some small correction factor for the increased
friction of the tires, wheels, and wheel bearings.

Note the "trick" of the question. It does not say that the conveyor keeps
the AIRPLANE at zero speed relative to the real world, just that it rotates
at a speed equal to the airplane moving forward. The question itself
supposes forward velocity of the aircraft relative to the earth and the only
thing the conveyor belt does is spin the wheels twice as fast.

Jim


Jim, you've got to realize that it must be a tough job being the
smartest man in the world.

I like being the second smartest. But as George Wallace once put it
after a reporter asked him, "You think that you're the smartest man in
the world?" No he said, "but I'm the smartest man in this room."

Mike Weller

And I'm not a George Wallace fan, for many reasons.

Mike Weller wrote:

On 3 Feb 2006 18:27:39 -0800, "cjcampbell"
wrote:

Saw this question on "The Straight Dope" and I thought it was amusing.

http://www.straightdope.com/columns/060203.html

The question goes like this:

"An airplane on a runway sits on a conveyer belt that moves in the
opposite direction at exactly the speed that the airplane is moving
forward. Does the airplane take off?" (Assuming the tires hold out, of
course.)

Cecil Adams (world's smartest human being) says that it will take off
normally.

No it won't.

And I'm surprised that I'm even responding to this.

Mike Weller

g

Let this be a lesson to you: whenever replying to a posted riddle or
puzzle that has over 100 replies, it might be a good idea to read some
of those replies to avoid falling into a well-set trap!

--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.

On Mon, 06 Feb 2006 14:11:45 -0500, alexy wrote:


Let this be a lesson to you: whenever replying to a posted riddle or
puzzle that has over 100 replies, it might be a good idea to read some
of those replies to avoid falling into a well-set trap!

Yes, and thank you. I've only touched the tip of the ice on this one.

Mike Weller

It was a joke James. I'll bet The Monk got it.





"Jim Macklin" wrote in message
news:UtqFf.75785$QW2.44974@dukeread08...
Category and class of aircraft...
aircraft includes all types of flying machines.

AIRPLANE does not include helicopters, see FAR Part 1

ASEL ASES AMEL AMES the A means category airplane and the
rest is the class
AMEL B747 includes the type.

Rotorcraft is the category and helicopter is the class.

--
James H. Macklin
ATP,CFI,A&P

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm
See http://www.fija.org/ more about your rights and duties.



"601XL Builder" wrDOTgiacona@coxDOTnet wrote in message
news:43E62B1E.6080403@coxDOTnet...
| Flyingmonk wrote:
| If you tie a 100 foot rope to the tail of an airplane
(or some other
| part of the airframe), attach it to a good strong post,
and run the
| propellor up to whatever rpm is available, is anyone
claiming the
| airplane can then lift up say a feet off the ground?
|
| (Assuming the tail doesn't tear off)
|
| (and, a conveyor belt under the airplane is optional)
|
| Depends on the airplane, if a plane is built in such a
way that it can
| actually attain enough lift just from the prop wash
alone than yes.
|
| The Monk
|
|
| Yeah Monk that airplane is called a helicopter.

It was a joke James. I'll bet The Monk got it.

Even if I didn't I'd pretend that I did. LOL

The Monk

"Flyingmonk" wrote in message
oups.com...
It was a joke James. I'll bet The Monk got it.

Even if I didn't I'd pretend that I did. LOL

The Monk


Damn straight you would!

"alexy"

avoid falling into a well-set trap!



I wouldn't call this a trap, it's simply a physics question that about 25%
of the respondents picks "won't take off".



Having gone through this once already in another group, the one thing that
stands out in my mind is that intelligence seems to have nothing to do with
how someone will answer. I have seen highly intelligent people insist that
the airplane won't move and they are willing to robustly defend their
position.



I would be at a loss to explain the difference between the minds of both
groups. Rick Durden's article suggests that those with engineering or math
backgrounds tend to side with the "will take off" group. I haven't seen
that correlation at all.





Dallas

Jon Woellhaf wrote:
CJ, please let us know when the light bulb finally goes on.

"cjcampbell" wrote

Still, it seems counterintuitive to me that if a plane is
sitting on a conveyer that is moving backwards at exactly the same
speed (I assume they mean groundspeed here) as the airplane is moving
forward that the airplane will move forward at the same speed as if it
was not on a conveyer at all.

Okay, I see why the plane moves forward normally no matter how fast the
treadmill is going and even why it would not work in an automobile.

As for that Monty Hall thing, I see that it works, but I have not
figured out why it works yet.

There are certainly some strange things in the world.

Now I have a headache. And they call me a troll and a Nazi. :-)

That's right, you troll posting, rat bast__d, head banging fascist!
Beginning a thread that *should* be able to be unraveled by a cross-eyed 6
year old, is evil, pure evil. I hope your head inflates to twice it's
normal size, before becoming pink mist! bfg

Well, at least the "pure evil" part is true!

This whole thing has been quite amazing. Who would'a thunk?
--
Jim in NC

176. cjcampbell
Feb 6, 9:41 pm show options

Newsgroups: rec.aviation.student, rec.aviation.piloting
From: "cjcampbell" - Find messages by
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Date: 6 Feb 2006 18:41:35 -0800
Local: Mon, Feb 6 2006 9:41 pm
Subject: Can a Plane on a Treadmill Take Off?
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"cjcampbell" wrote

Okay, I see why the plane moves forward normally no matter how fast the
treadmill is going and even why it would not work in an automobile.

Well, not exactly. This dead horse is fun to beat. Suppose I tell you
the car is going forward at 60 mph. That means the belt is going the
other way at 60, right? The speedometer would be indicating 120.

The OP said the belt is moving backward as fast as the whatever is
moving forward. When you substitute real numbers into the thing it
becomes more clear.

Or not.