Riddle me this batman

[maryannette]

It was rigged.

 

[Sschell]

not this thread again!

 

[FLBuff PE]

Can't help it, sorry. :deadhorse:

 

[Sschell]

dude.

 

[sehad]

Ok, I know everyone is tired of this threat. BUT, explain to me please how the plane flies? As stated earlier, the wings are what cause uplift on the plan and the air has to be going a certain velocity for this to happen. So in my mind(understanding I've never designed an airplane), significant forward movement of the wings must happen. How does the plane get lift?

edit: I'm not reading the entire pages but I do have one question. Someone on the first page was saying that the thrust of the engine acted on the air not the ground so it would still move. Didn't is say that the belt was a reaction to the forward movement of the plane? If so, as the plane accelerated by force on the air, the belt would increase in speed to match that.

DID THE THING ACTUALL FLY?

 

[mudpuppy]

Does this clear things up for you at all?

Ok, I haven't weighed in on this. So let me try (yet) another approach at explaining this in the off chance that DV is not correct in his conspiracy theory.
Let's say we have the plane sitting motionless on the conveyor. Let's say it's a small plane; small enough for a couple of people to easily push around. Now say a couple people off to the side of the conveyor (feet on solid ground) approach the plane, one on either side, and push forward equally on each wing with enough force to overcome friction. Does the plane move relative to the ground?

If you think it does not, please explain what the conveyor is doing to prevent the plane from moving when an external force is applied to it. In order to keep the plane from moving, an opposite force of equal magnitude must be applied. As far as I can see, there is no way for the conveyor to apply this force--if the conveyor moves forward, the plane moves forward with it. If the conveyor does not move, the plane rolls forward. If the conveyor moves backward (as the riddle states), the plane rolls forward with its wheels spinning faster.

If you think the plane does move relative to the ground, then (assuming no wind) it must be moving relative to the air around it as well, which I think we all agree causes lift. If you replace the force applied by the people with the thrust provided by an engine (propeller, turbine or whatever), it will still move--force is force, whether it is applied against the ground or against a fluid. And I think we all agree that if the plane can move forward it can continue to accelerate to takeoff velocity.

 

[IlPadrino]

Ok, I know everyone is tired of this threat. BUT, explain to me please how the plane flies? As stated earlier, the wings are what cause uplift on the plan and the air has to be going a certain velocity for this to happen. So in my mind(understanding I've never designed an airplane), significant forward movement of the wings must happen. How does the plane get lift?
edit: I'm not reading the entire pages but I do have one question. Someone on the first page was saying that the thrust of the engine acted on the air not the ground so it would still move. Didn't is say that the belt was a reaction to the forward movement of the plane? If so, as the plane accelerated by force on the air, the belt would increase in speed to match that.

DID THE THING ACTUALL FLY?

You have to read every post on this thread and build your own model (to scale!) before I'll entertain (key word: entertain!) any more discussion on this. I do understand why many get this wrong before they really think it through, but for the life of me, I'll never understand how a competent engineer can't understand this after MUCH discussion.

 

[sehad]

You have to read every post on this thread and build your own model (to scale!) before I'll entertain (key word: entertain!) any more discussion on this. I do understand why many get this wrong before they really think it through, but for the life of me, I'll never understand how a competent engineer can't understand this after MUCH discussion.

Sorry that I haven't been involved in the MUCH discussion and I didn't read all 7 pages due to the time it would take and I'm sure some of the discussion gets pretty technical as I can tell by the tone in your post. BUT, I will be sitting down tomorrow to think this through.

 

[benbo]

Sorry that I haven't been involved in the MUCH discussion and I didn't read all 7 pages due to the time it would take and I'm sure some of the discussion gets pretty technical as I can tell by the tone in your post. BUT, I will be sitting down tomorrow to think this through.

It took me a little while to get it. THe main thing you have to get past is the notion that the treadmill can exert any real effect on the plane. Except for some minimal friction, the wheels of the plane just roll freely.

I actually had to get a little matchbox car and push it on my exercise treadmill. No matter how fast the treadmill turns it can't do anythiing to the car. If the car goes forward at one foot per second and the treadmill goes backwards at one foot per second, the wheels just spin faster.

 

[sehad]

I conceed. She flies. I usually have to draw things out so I did. Right now my wife is going through some rant about how big of a nerd that I am!

The only force resisting the thrust of the plane is drag and friction of the wheel. The plan will take off slightly slower than usual becaue there is some force there, even though it may be minimal. It still seems to go agains logic and common sense. I'll have to try my brother in law with this one. He's in school for engineering now.

I like these brain teasers as well!

 

[IlPadrino]

I conceed. She flies. I usually have to draw things out so I did. Right now my wife is going through some rant about how big of a nerd that I am!
The only force resisting the thrust of the plane is drag and friction of the wheel. The plan will take off slightly slower than usual becaue there is some force there, even though it may be minimal. It still seems to go agains logic and common sense. I'll have to try my brother in law with this one. He's in school for engineering now.

I like these brain teasers as well!

Oohrah! You're restored my faith in humanity!

I, too, really enjoy brain exercises. I'll start another one we were just discussing the other day.

 

[FLBuff PE]

Sehad, Fudgey posted this. IMHO, it is the best reponse to this thread ever posted on this board...

 

[sehad]

^^^Can't see whatever it is

 

[FLBuff PE]

Funny pic thread, page 5. You may have to view it at home (damn internet firewalls/filters).

 

[engineergurl]

so... if i flap my arms while running on a treadmill I will take off flying forward instead of tripping and flying off the back like I normally do... :Locolaugh:

 

[csb]

only if your arms agree with Bernoulli...

 

[engineergurl]

By the way... there are too many posts for me to read all the MUCH debate... but this was on mythbusters.... so I say

THE PLANE WILL TAKE OFF!

(Right now I don't think my arms would agree even if my mind does!)

 

[sehad]

It'll takeoff. Other thanthat, who cares!

 

[FLBuff PE]

You guys just don't understand that one of the points of this thread is to :deadhorse: and incite riots!

 

[sehad]

yea yea yea!