Airplane physics question

This aircraft would take off with the brakes on LOL

 

Aplogies to Bette Midler
-

It must have been cold there on the radar,
to never have movement on that space.
Some were content to let jets whine o'er runway,
some always post a step behind.

So we were ones who stuck with the story,
And we're all amazed by the thread's length.
A whimsical thread about a plane -- for so long,
a conveying mile to ground the plane.

CHORUS:
Did you ever post that plane goes zero,
or ev'rything it would take to speed?

It can't fly higher than an eagle,
'cause conveyor belt's beneath it's wings.

It might have appeared to go - Mythbusters,
but it was all so flawed from the start.
I want you to know I know the truth, of course I know it,
This thread is nothing without you.

(CHORUS)

Fly, fly, fly away?
Could it yet fly so high?
Oh, fly, fly?
so high against the sky, so high I almost touch the sky?
Hell no, hell no, hell no, won't go,
the belt beneath it's wings.

 

The Belt, the Belt, ahh that belt
Confusion reigned on high
But that won't keep a beautiful wing
From touching it's home...the sky.

The length of the thread makes some apathetic
But not to those who know,
That given the wonderous beauty of time
it's bound to wax poetic.

And when it does, we'll all look back, once the deed is done
and ask ourselves, in the still of the night...
"Twas it worth it? Was it fun?"
The answer to which might fright.

But fear is only a witchman's tale
won't reach the light of day.
We'll know for sure the plane took sail,
or else, we're left to pray.

 

Okay, I shut up........

 

And in so doing, I'm smarter than I look! Or dumber. Heeeyyyyyyyyyyyyy, wait a minnnnnnutttttte...

I'm beholden to strict "yeah, BUT" controlled laboratory-worthy conditions, in which the air is stagnant as in vacuo, so while wheel and surface friction exists to infinity, there is no air friction.

It doesn't fly.

*Runs*

 

I still think it's hilarious that I predicted 8 pages when I posted this. Little did I know.

 

"In vacuo", the engine won't run, the pilot won't breathe.

Give up, it's done.

 

What about a car on a dyno? Why does it not over power the rollers and take off out the front door of the shop, or go through a wall? Is the airplane on a tread mill not the same basic idea? I know the aircraft does not use power at the wheels for forward motion, but if the wheels are what is used to transfer engine thrust to the ground to allow the aircraft to roll forward, why then if the tread mill is basicly acting like the rollers on the dyno, would the aircraft take off?

 

Egg-zackly!

*Obligatory Ace Ventura Victory Dance*

 

no

no thrust is being transfered "to the ground". It's being transfered to the air above the ground...

If you tied one end of a rope around the bumper of a car on a dyno, and the other end to a winch fastened to the floor of the garage, and turned on the winch, the car would be pulled from the dyno.

 

Original question...

The conveyer belt is designed to exactly match the speed of the wheels at any given time, moving in the opposite direction of rotation.
There is no wind.
Can the plane take off?

1) If you ignore the language used in the question and presume that the wheels can be allowed to rotate faster than the belt then the plane takes off.

2) If you stick rigidly to the meaning of the (very cleverly written) question, then the plane cant move because as soon as it does it breaks the questions limits.

 

Got to play this...
Image Unavailable, Please Login

 

*God not this **** again*
*ahem*

Here's some basic info about planes. The thrust does NOT go to the wheels. An airplane can take off without wheels, hence seaplanes. The thrust from the engines forces the plane forward due to the laws of thermodynamics. The thrust from the engines causes an equal but opposite reaction, aka the plane moving forward. This is all independant of the wheels. Planes only have wheels because it maks for easier takeoffs and landings. Of course, this doesn't answer how a place could fit on a treadmill

 

Wax has hinted that this revival of the "Mother of All Time Wasters" was a well-timed activity booster.

 

The plane DOES fly. The thrust is created from the jets, not the wheels. The treadmill would have no effect. It's just thrown in the equation to create confusion.

 

Only if its wheels rotate faster than the belts, oops the question says that cant happen...

The basic premise of the question is that the wheels have to match the speed of the conveyor. For this to be upheld there can be no external force applied to the plane (i.e. its engine cant provide thrust as doing so would break the rules). With no thrust from the engine the planes wheels won't move which means neither will the belt.

The only state where everything matches the questions limits is a stationary plane and stationary belt. As soon as thrust is applied for take-off then the plane will indeed take-off BUT that would then break the limits set out by the question.

So, in answer to the question, no the plane won't take-off (given the questions limits).

 

The "gist".

 

I'm amazed this is still going.

 

Wow! Page 95, 1896 responses, 18301 views.

.....but only 77 votes?!?!?!?!

 

I'm tellin' you right now - it won't fly.

 

This was done on Mythbusters (sorry if that's a repost - I'm NOT going to read
1800 threads to find out!). Plane on LONG 'treadmill' being pulled in opposite
direction of running plane configured for take-off. Took off just fine. 'Treadmill'
(and therefore the wheels) had absolutely NOTHING to do with it.