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airplane vs conveyor belt

Dec. 23, 2007, 11:18 p.m.
Posts: 54
Joined: Aug. 3, 2006

http://www.pinkbike.com/forum/listcomments/?threadid=13560[HTML_REMOVED]pagenum=8

The plane would fly. Better than that, tune in to Myth Busters on Jan30th when they run a real life trial…..

http://www.youtube.com/watch?v=siYQU99VaAM

http://www.youtube.com/watch?v=KSBFQOfas60

Yes the plane takes off….again and again, man I hope Mythbusters agree on Jan 30th!

nate

Dec. 23, 2007, 11:20 p.m.
Posts: 54
Joined: Aug. 3, 2006

This how i see it,

1st, the plane is sitting still on the runway.

2nd, the engine starts, and pushes/pulls on the air

3rd, because the engine is pushing/pulling on the air, it must move forward

4th, at moves forward and the wheel accelerate up to infinity

5th, the wheels seize or explode, and depending on how much power the engine has
a) It just skids across the runway and takes off,
b) It just sits there because it wheels are broken and it cant move

Haha I agree 100%, except the part about the wheels accelerating to infinity, because the plane only needs to reach a set speed to take off, at take off the wheels will be turning at twice their normal speed….that's my theory.

nate

Dec. 23, 2007, 11:45 p.m.
Posts: 54
Joined: Aug. 3, 2006

"The conveyer belt is designed to exactly match the speed of the wheels at any given time, moving in the opposite direction of rotation"
Taken from the first post, the original question.

Ok - plane fires jet engine, wheels rotating speed has to increase, this we agree on, the statement above says the conveyor will simply match it's speed, by whatever means, that we don't need to know. Black magic, voodoo, witchcraft, whatever, it JUST does, so what? Now you still have a plane moving forwards just with wheels and a treadmill turning a little faster than before, like youtube guy said, the rotating speed of the treadmill (and therefor the wheels) has absolutely no impact on the situation…..

"The conveyor belt is designed to exactly match the speed of the wheels at any given time" to me does not say this speed is not allowed to increase, all it does say is that when the rotating speed of the wheels does increase (at that very instant, or simultaneously, same thing) the conveyor will also increase it's speed to match. ….. because of that, once again, yes the plane can move forwards and therefor fly.

Also, once again, this comes down to more of an english language argument than a physics one. The question is not inclusive enough to limit the scenario to make you right, it doesn't state "the speed of the wheels or the conveyor can not change, can the plane take off?" It simply says the conveyor will always match the speed of the wheels. Once again, if it were a car, you would be right, stationary object. Car with a jet engine on the roof, forward movement.

nate

Dec. 23, 2007, 11:48 p.m.
Posts: 0
Joined: Nov. 20, 2002

Once again, if it were a car, you would be right, stationary object. Car with a jet engine on the roof, forward movement.

nate

and when it moves forward the wheels are….?

turn off sigs…it will change your life

Dec. 23, 2007, 11:56 p.m.
Posts: 2241
Joined: July 3, 2006

Hey GB - if a conveyor is moving backwards at the same speed as the wheels are rotating forward, then the wheel itself can't move forwards. Mythbusters will, of course, miss this fine point, try to take off a plane from a conveyor belt without this limitation, and pat themselves on the back.

If the wheels (and plane) move forward, then the conveyor ISN'T matching the speed of the wheels.

The question you're answering (and the question Mythbusters will test) is 'Can a plane take off from a moving conveyor belt' - the answer to which is 'of course it will, what kinda moron are you?'

Dec. 24, 2007, 12:12 a.m.
Posts: 0
Joined: June 1, 2006

Yea I always seem to forget the part about the treadmill going the EXACT same speed as the wheels. The plane can then never move. No air over the wings means no fly.

Dec. 24, 2007, 12:29 a.m.
Posts: 132
Joined: Dec. 28, 2005

alright….. last post on this thread. THE PLANE TOOK OFF. There is proof from DB Cooper himself. On his death bed he revealed the real reason he jumped out of the plane. Disco was sitting next to him talking his ear off and imajin on the other side pimpin his jeans. Also DB joined the mile high club with PCH, but couldn't take the nbr-esque rambling and jumped….

On his death bed he said, "I',m DB cooper, and the plane took of from said conveyer belt bitches".

Dec. 24, 2007, 1:15 a.m.
Posts: 8350
Joined: Jan. 18, 2004

A fitting final post indeed. ^^^

But looks like I just ruined it.

Nice Christmas Card, Nat.

Dec. 24, 2007, 8:47 a.m.
Posts: 54
Joined: Aug. 3, 2006

The question states that the conveyor is designed to always match the speed of the wheels, it doesn't say this speed isn't allowed to change, wheels rotating speed increases as the plane moves forward, the conveyor simultaneously increases it's speed to match (because it says so in the question) you still have a plane moving forwards, just with faster spinning wheels than when it was at a stand still on the moving conveyor….I dunno, the wording of the question isn't inclusive enough I guess and that's why it's such an argument, it depends on how you understand the wording….to me, that's how it is.

nate

Dec. 24, 2007, 8:50 a.m.
Posts: 4905
Joined: Aug. 7, 2007

This how i see it,

1st, the plane is sitting still on the runway.

2nd, the engine starts, and pushes/pulls on the air

3rd, because the engine is pushing/pulling on the air, it must move forward

4th, at moves forward and the wheel accelerate up to infinity

5th, the wheels seize or explode, and depending on how much power the engine has
a) It just skids across the runway and takes off,
b) It just sits there because it wheels are broken and it cant move

4th. is false, It does not move forward, that's the whole debate is about with the conveyor belt.

Dec. 24, 2007, 10:39 a.m.
Posts: 0
Joined: Nov. 23, 2005

I have a question for everyone. What does "The conveyer belt is designed to exactly match the speed of the wheels at any given time, moving in the opposite direction of rotation." mean to you?
Is the belt simply moving at the same rate of the wheels but in the opposite direction? Is the belt moving at a rate that is fast enough to cause the wheels to remain geographically still?

Eric

Dec. 24, 2007, 1:28 p.m.
Posts: 5334
Joined: Feb. 3, 2006

Is the belt simply moving at the same rate of the wheels but in the opposite direction? Is the belt moving at a rate that is fast enough to cause the wheels to remain geographically still?

If the belt is moving at the same rate in the opposite direction, The wheels are staying geographically still.

Dec. 24, 2007, 1:42 p.m.
Posts: 0
Joined: Nov. 23, 2005

If the belt is moving at the same rate in the opposite direction, The wheels are staying geographically still.

Ok, so you are basing your wheel speed against is rotation, not in relation to geographic location. Next.

Eric

Dec. 24, 2007, 2:09 p.m.
Posts: 0
Joined: Nov. 20, 2002

Ok, so you are basing your wheel speed against is rotation, not in relation to geographic location. Next.

i like to read questions first and then answer them

you?

turn off sigs…it will change your life

Dec. 24, 2007, 2:27 p.m.
Posts: 0
Joined: Nov. 23, 2005

I prefer to understand them after I read them,
you?

Eric

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