A jet plane on a large treadmill

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02-21-2007, 01:22 AM
huck4bucks

Quote:

Originally Posted by f2f

are you saying the threadmill can spin at a speed larger than the speed of light? i'll tell you what then: nothing. and everything.

stop "thinking" and start thinking.

I can't think anymore. Sell the treadmill to the girls' track team and give the plane back to Boeing.

Personally, I think it's a great explanation on the thread next door. That makes sense to me. The question was never worded correctly and specifics are purposefully left out to create mass hysteria, which we've seen here over the past 20+ pages.
02-21-2007, 09:31 AM
DJSapp

w00t!!! page 20!!!! Plus another 5 in a second thread!!!

Rolling friction does not increase with speed. The rolling friction on a 747 is 78,000 lbs. 78,000 lbs of resistance is all the treadmill can possibly provide no matter what speed the treadmill is spinning at. It could be going twice the speed of light and it would only provide 78,000 lbs. of resistance.

The 747's engines provide 380,000 lbs. thrust.

380,000 is bigger than 78,000

THEREFORE:

There is a net force (read: acceleration) of 302,000 lbs. on the airplane.

If you don't understand this, open a fucking physics book and get a fucking education.
02-21-2007, 09:35 AM
pechelman

DJSapp
You're one persistant fellow to keep goin at this

everyone seriously
just look at the stupid motorcycle picture, its the same thing

imagine what would happen if you had a tow rope sucked into the turbine and shot out the other end. the plane would move along the tow rope and the wheels would just be spinning twice as fast. (ie im saying just imagine the wings\turbines were attached to a tow rope like at a ski resort)

thats my final post here
02-21-2007, 04:23 PM
Lonnie

How about a helicopter? Could it take off if sitting on a treadmill?
02-21-2007, 04:56 PM
f2f

^ you can't win against a cold, calculating, malevolent and omnipotent threadmill.
02-21-2007, 05:02 PM
The AD

I know what a treadmill is. Now please tell me WTF a threadmill is.
02-21-2007, 05:10 PM
f2f

it's a mill for threads. or a misspelling. you choose.
02-21-2007, 06:00 PM
couloirman

this is fucking rediculous, of course the plane takes off. No treadmill can stop the motion of a plane once the engines turn on. The jets turn on, the plane moves forward at the same speed as usual, and the wheels spin like mad and dont do anything. Jesus, 20 pages for this.
02-21-2007, 07:25 PM
P_McPoser

AD, THIS QUESTION is a thredmill.
02-24-2007, 02:59 PM
AsheanMT

Just in case some of you have become confused by these 20 pages let me simplify the whole damn thing by giving you the answer....

THE PLANE WILL TAKE OFF.

If you don't understand how it could then thats too bad for you just deal with it.
02-24-2007, 03:17 PM
MeatPuppet

Quote:

Originally Posted by Lonnie

How about a helicopter? Could it take off if sitting on a treadmill?

Better yet, what about a helicopter sitting on a merry-go-round that is spinning in the opposite direction as the blades, matching their rotation?;)
02-24-2007, 04:29 PM
AsheanMT

Quote:

Originally Posted by MeatPuppet

Better yet, what about a helicopter sitting on a merry-go-round that is spinning in the opposite direction as the blades, matching their rotation?;)

W00T!! LOL!! The helo takes off methinks:cool:
02-24-2007, 04:36 PM
Reno

What's the proportional snake loading between the merry-go-round and the helicopter?
02-24-2007, 04:48 PM
MeatPuppet

Quote:

Originally Posted by Reno

What's the proportional snake loading between the merry-go-round and the helicopter?

Black on yellow kill a fella?
02-25-2007, 10:09 PM
Blurred

Quote:

Originally Posted by "The Big One"

A plane (747 passenger jet) is sitting on a runway that can move (some sort of band conveyor). The plane moves in one direction, while the conveyor moves in the opposite direction. This conveyor has a control system that tracks the planes speed and tunes the speed of the conveyor to be exactly the same (but in the opposite direction).

The question is:

Will the plane (747 passenger jet) take off or not?

Without reading this whole thread......
Of course the plane would fly.
Jet planes operate off of thrust which gets it's propulsion from the air. If planes took off by using torque to tires like a car, then the "conveyor" would be relevant. In this case, it's not. The conveyor would just spin the wheels on the plane twice as fast. ;)

Here's an even tougher question- What weighs more?

A pound of feathers or a pound of gold?
02-25-2007, 10:18 PM
summit

But what if there are MOTHERFUCKING SNAKES ON THE MOTHERFUCKING TREADMILL!?
02-25-2007, 10:20 PM
AsheanMT

Quote:

Originally Posted by Summit

But what if there are MOTHERFUCKING SNAKES ON THE MOTHERFUCKING TREADMILL!?

then we all would be motherfucked!
02-26-2007, 02:07 PM
telepariah

This plane with take off, motherfucking snakes or none.

Blurred has it exactly right.
02-26-2007, 02:47 PM
PearlJam09

Quote:

Originally Posted by Bernardo

Credentials: I'm an Aerospace Engineer AND Mathematician.

Solution: The airplane WILL take off.

Explanation: Thrust is provided by the jet engines. Thrust is needed to overcome Drag. Drag is made up of aerodynamic drag, and friction drag on the wheels. The friction drag on the wheels/bearings will be *marginally* higher on the spinning treadmill, but will continuously diminish as the airplane gains speed and the lift increases, thus reduction wheel friction.

Source of confusion: The problem statement is slightly confusing because it says something about the treadmill spinning at the same speed of the aircraft. This could induce some people to believe that the two velocities cancel each other out, whereas the truth is that the wheels will simply spin twice as fast (remember, the wheels of the aircraft are free spinning).

- B

I'm changing my POV. I'm with this guy. Stupid freespinning wheels, confusing me. If somehow the wheels were restricted to spin only as fast as the air speed was then the velocities would negate each other, but with freespinning wheels, I now think that this would take off.
02-26-2007, 02:52 PM
yodaottis

I have: a really old pair of rollerblades somewhere
I have: some rope

If you have:
A motorcycle
A treadmill

Then we need to make this happen. We can then track down and send invitations to the 40 or so people that voted for "no take off" in the other thread and get them here to try it out.

Who's your dead friend there?
Cause he's dead.
*points @ dude on treadmill with rollerblades*
02-26-2007, 03:43 PM
Franz Klammer

Quote:

Originally Posted by yodaottis

I have: a really old pair of rollerblades somewhere
I have: some rope

If you have:
A motorcycle
A treadmill

Then we need to make this happen. We can then track down and send invitations to the 40 or so people that voted for "no take off" in the other thread and get them here to try it out.

Who's your dead friend there?
Cause he's dead.
*points @ dude on treadmill with rollerblades*

Well, actually, the dead dude would be off the treadmill :fm:
02-26-2007, 08:33 PM
seldon

Quote:

Originally Posted by BlurredElevens

Without reading this whole thread......
Of course the plane would fly.
Jet planes operate off of thrust which gets it's propulsion from the air. If planes took off by using torque to tires like a car, then the "conveyor" would be relevant. In this case, it's not. The conveyor would just spin the wheels on the plane twice as fast. ;)

Here's an even tougher question- What weighs more?

A pound of feathers or a pound of gold?

Pound of feathers - gold is measured in troy units - 14oz to a pound.
03-18-2007, 06:36 AM
Tectonically_Neglected

A youtube vid

So, for those who had problems with 'The jet plane on a large treadmill' thread... what happens if the speed of the escalator is increased?
03-18-2007, 08:34 AM
P_McPoser

He'd stop obviously.
03-18-2007, 11:33 AM
Chinaski

speaking of superthread....

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