8

1/29/2008 5:52:26 PM

study some basic aerodynamics...if the plane is going 180mph in direction X, on the treadmill, and the treadmill is going 180mph in direction -X, (or -180mph velocity in X direction), the overall velocity will be 0...the air velocity is what really matters since its LIFT that LIFTS planes into the air, not speed relative to the ground

1/29/2008 5:54:40 PM

Quote :

"well, the whole question is pointless, since all other things being equal, the treadmill has no significance. "

That IS the point of the question. That some people don't realize the treadmill has no affect.

1/29/2008 5:55:12 PM

no effect

AND YOU DON'T BURY SURVIVORS!!!111

unless you're torturing a motherfucker by burying him alive

1/29/2008 5:56:09 PM

Quote :

"Ok, let me use this example again for those of you out there that still think the plane will not take off. You have a friend who is wearing roller skates. Think of him as being the plane. He is standing on one of those moving sidewalks(the treadmill) they have at the airport. It is not turned on yet. You are standing to the side on stationairy ground with your hand against your friends back. The moving sidewalk is turned on at this point to a speed of say 5mph. Your friend is remaining stationary because the small amount of force you are putting on his back is holding him in place. Imagine the force of your hand pushing on his back is the thrust of the engines. No matter how fast the treadmill goes, it required the same amount of force to hold him in place. Now say they crank up the treadmill to 180mph, the speed it takes most planes to take off, your hand against his back is still holding him right in place. At this point you begin to walk at a nice steady pace of 6 mph while pushing him along the moving sidewalk. If you don't think it will take off, then explain to me how the moving sidewalk can be going 180mph in one direction, while I am pushing my friend, with total ease, at only 6mph in the other direction. By your logic, I would have to be running at 186mph while pushing him in order to move him forward at 6mph. The plane is free to move forward at any speed regardless of how fast the treadmill is moving in the opposite direction. Do you understand now that the plane will take off? "

^Read this again.

[Edited on January 29, 2008 at 5:56 PM. Reason : .]

1/29/2008 5:56:20 PM

2nd post on this page is the one i stand by all along

[Edited on January 29, 2008 at 5:57 PM. Reason : ]

1/29/2008 5:57:28 PM

can a plane take off in a vacuum?

1/29/2008 5:57:42 PM

like an electrolux?

1/29/2008 5:58:01 PM

that dude from the Oreck commercials seems like he'd be a kind grandfather

but obviously a space shuttle can use thrusters in the vacuum of space...but thats unidirectional since theres no gravity...theres gravity on earth so the plane needs air underneath to take off, regardless of the irrelevant treadmill's velocity

i'm sure all this has been mentioned earlier in the thread though, i got in late

[Edited on January 29, 2008 at 5:59 PM. Reason : .]

1/29/2008 5:58:24 PM

i bet he'd always have a werthers original

1/29/2008 5:59:11 PM

Quote :

"2nd post on this page is the one i stand by all along"

Then why am I able to push someone wearing roller skates at 6mph along a moving sidewalk going 180mph in the opposite direction. Am I running at 186mph? Because using your logic, that is what I would have to be doing.

1/29/2008 6:00:09 PM

do the roller skates have wings on them? cause otherwise i dont know why you're comparing an airplane to roller skates

planes dont take off, physics-wise, strictly from speed relative to the ground...its that speed, which makes relative wind / air speed in the opposite direction fast enough to cause lift

[Edited on January 29, 2008 at 6:02 PM. Reason : .]

1/29/2008 6:00:50 PM

1/29/2008 6:01:46 PM

^^ you're assuming that the plane is not moving relative to the non-treadmill ground/air, in which case you'd be right.

1/29/2008 6:02:55 PM

exactly, and thats the case if i understand the setup correctly

i think some people are understanding the velocity vector aspect but not the aerodynamics of lift and flight aspect

1/29/2008 6:04:11 PM

dale earnhardt was going 180 when he hit the wall

if your logic was correct, then he would have flown over the wall...or something

im not going to e-argue, but i am entitled to believe what i want to believe

1/29/2008 6:04:39 PM

What are you even talking about?

There is lift generated by the wind speed acting upon the wings as the plane travels down the treadmill.

^haha, I expected a better response after totally owning you. I guess you have nothing to reply with since people can't run 186mph huh?

Sure, you can think what you want, but that doesn't mean its right.

[Edited on January 29, 2008 at 6:06 PM. Reason : .]

1/29/2008 6:05:24 PM

are you saying the treadmill is dragging wind enough to lift a plane

1/29/2008 6:05:53 PM

how do you travel down a treadmill?

1/29/2008 6:06:13 PM

Quote :

"treetwista: if the plane is going 180mph in direction X, on the treadmill, and the treadmill is going 180mph in direction -X, (or -180mph velocity in X direction), the overall velocity will be 0"

Actually, if the plane is going 180mph in X, it would have already taken off.

The treadmill can't in any meaningful way affect the motion of the plane. There is no point in time, except when the plane is stopped, that its velocity is 0 relative to anything. Because its the engines that's moving it, it's speed relative to the treadmill will be the exact same (less a little bit of friction) as a plane not on a treadmill.

[Edited on January 29, 2008 at 6:06 PM. Reason : ]

1/29/2008 6:06:24 PM

^^by exerting more force against friction with the treadmill than it is exerting against you.

[Edited on January 29, 2008 at 6:07 PM. Reason : asdf]

[Edited on January 29, 2008 at 6:09 PM. Reason : fixed]

1/29/2008 6:07:04 PM

there's a reason airplanes move parts of their wings around during takeoff

1/29/2008 6:07:11 PM

^^ a plane can't actually exert force against the treadmill though.

[Edited on January 29, 2008 at 6:07 PM. Reason : ]

1/29/2008 6:07:34 PM

Quote :

"Actually, if the plane is going 180mph in X, it would have already taken off"

but the -180mph of the treadmill would mean the net velocity is 0 in which case it wouldnt do anything but keep spinning like Ferris Bueller's friend Cameron's dad's Ferrari before he hit the release and that bitch flew out the window into the woods

1/29/2008 6:07:42 PM

^ a car accelerates by applying power to the wheels, which push against the ground.

A plane accelerates by pushing against the air (not really, but practically).

Think of a sea plane or an ice plane taking off. The skids don't move at all. The planes wheels are free spinning, there's no engine moving the wheels.

That's why people use the tonka truck/roller blades on a treadmill, because the wheels in those things are free-spinning.


[Edited on January 29, 2008 at 6:09 PM. Reason : ]

1/29/2008 6:08:41 PM

^^You are obviously just trolling, but let me just prove you wrong again.


Now say they crank up the treadmill to 180mph, the speed it takes most planes to take off, your hand against his back is still holding him right in place. At this point you begin to walk at a nice steady pace of 6 mph while pushing him along the moving sidewalk. If you don't think it will take off, then explain to me how the moving sidewalk can be going 180mph in one direction, while I am pushing my friend, with total ease, at only 6mph in the other direction. By your logic, I would have to be running at 186mph while pushing him in order to move him forward at 6mph.

[Edited on January 29, 2008 at 6:10 PM. Reason : .]

1/29/2008 6:09:04 PM

the only way i see it working is if it has some sort of Harrier capability

but i just dont understand how people totally ignore the fact some upward force needs to make the plane take off

1/29/2008 6:10:25 PM

^^ I think dweedle is trolling, I don't think twista is.

^ that's what you don't understand, if the plane is using its engines as it normally would to take off, it's like the treadmill is not even there. The plane is just going to acclerate like normal.

1/29/2008 6:11:15 PM

How can sea planes take off??

THERE ARE NO WHEELS!!!!!!

1/29/2008 6:11:18 PM

what makes any indication im trolling

1/29/2008 6:11:55 PM

HOW CAN SEAPLANES TAKE OFF UPSTREAM?

1/29/2008 6:12:17 PM

YA ITS LIKE THAT TIME ON MALCOM IN THE MIDDLE WHEN THEY WENT IN REVERSE TO THE HOSPITAL!!1

1/29/2008 6:12:30 PM

^^^ you keep repeating the same thing, without regard for other peoples' previous responses to your statements.

[Edited on January 29, 2008 at 6:12 PM. Reason : ]

1/29/2008 6:12:32 PM

You have to be an idiot to think this thing can fly, there are no wheels on it.

1/29/2008 6:14:08 PM

i wonder how much extra storage they added to the mythbusters email servers for all the half of america thats gonna be cussing them out next week, no matter the outcome

1/29/2008 6:14:23 PM

Well most of us already know the outcome.

1/29/2008 6:15:31 PM

so..
180 in one direction for the treadmill
180 in the opposite direction for the airplane

0 net velocity with respect to the ground


you say something about pushing it 6 mph from behind i assume

thats +6 mph to the +180mph its already going against a -180mph....sure the plane would travel 6 mph down the treadmill

1/29/2008 6:16:18 PM

The trick is that the wheels are FREE SPINNING. GET THIS IN YOUR HEAD.

on a car (that's not in neutral) the wheels are NOT free spinning. On a plane, in all situations, the wheels ARE free spinning. That's the difference between a car (or your legs) NOT being able to move on a treadmill, relative to a fixed reference point, and a plane BEING able to move on a treadmill, relative to a fixed reference point.

1/29/2008 6:16:24 PM

Quote :

"study some basic aerodynamics...if the plane is going 180mph in direction X, on the treadmill, and the treadmill is going 180mph in direction -X, (or -180mph velocity in X direction), the overall velocity will be 0...the air velocity is what really matters since its LIFT that LIFTS planes into the air, not speed relative to the ground"

pretty much sums up 8 pages of retards who think it still lifts off. Aero engr's gotta be doing the carl face when they see this shit.

1/29/2008 6:16:27 PM

^ uhh... pretty much all the engineers agree that the plane will lift off.

1/29/2008 6:17:28 PM

someone in the "it flies" group explain again what contributes to vertical velocity

1/29/2008 6:18:21 PM

Quote :

"so.. 180 in one direction for the treadmill 180 in the opposite direction for the airplane"

Okay, on the airplane here, are its engines on or off?

1/29/2008 6:18:23 PM

i assume they have to be on

1/29/2008 6:19:07 PM

Quote :

"you say something about pushing it 6 mph from behind i assume thats +6 mph to the +180mph its already going against a -180mph....sure the plane would travel 6 mph down the treadmill"

Do I have to run 186mph in order to push someone on roller skates 6mph in the opposite direction of a treadmill going 180mph? Nope, I only have to push him 6mph. Why? Because the treadmill has no effect.

1/29/2008 6:19:16 PM

i agree with any horizontal motion on that, just no vertical motion

1/29/2008 6:19:59 PM

when the hell does this come on TV anyway

1/29/2008 6:20:34 PM

Quote :

"i assume they have to be on"

So if the engines are on, then how on earth are the wheels going to get up to 180 mph?

Think of a Tonka truck. Considering its wheels, like an airplanes, are free spinning, how would you make its wheels reach 180 mph?

[Edited on January 29, 2008 at 6:21 PM. Reason : ]

1/29/2008 6:20:53 PM

Vertical motion is created by the lift that is generated by the air moving over the wings. And there is air moving over the wings because the plane is moving forward.

1/29/2008 6:21:28 PM

ah i think i see what ur getting at then


but i still only agree with horizontal motion




so this myth, all along i thought it was saying that the plane would stay horizontally still, and that it would just levitate at some point. so has it involved horizontal motion all along?

[Edited on January 29, 2008 at 6:23 PM. Reason : ]

1/29/2008 6:21:55 PM

Do you also think that planes just ride around like cars then? Because going by your logic, thats what you are claiming.

^yes, it has.

Glad you could join us over on the side of common sense.

Quote :

"all along i thought it was saying that the plane would stay horizontally still, and that it would just levitate at some point."

The myth never said that, you just assumed thats what would happen.

[Edited on January 29, 2008 at 6:26 PM. Reason : /]

1/29/2008 6:22:53 PM