JC, I'll stop bitching when you draw me the force diagram that shows the equal and opposite force to the engine thrust that prevents the plane from moving. ;)

Wish I had seen this earlier...

The question is a paradox and has no solution. Theere are two physical systems that are both mutually dependent, and dicontinious at the same timee that generate conditions that mutual exclusive.

The first system is the wings, and airspeed. This combination is the only thing that can lift the plane.

The second system is a belt and planes wheels. "The conveyer belt is designed to exactly match the speed of the wheels at any given time, moving in the opposite direction of rotation."


Since the plane is at rest to begin with "is sat on the beginning of a massive conveyor belt" Wheel speed is zero, and since there is no force directly applied to the wheels, they can never spin since "The conveyer belt is designed to exactly match the speed of the wheels at any given time, moving in the opposite direction of rotation" -0 +0 = 0 . The wheels can never turn. There are no provisions in the premis for the conveyor belt to move for any other reason, other than the wheels rotating, so it can never turn. This is the limiting factor in the wheel/conveyor belt system.

The plane of course though can thrust all it wants, and that force should cause motoin, airspeed, and eventually lift. But the tires/conveyor belt cannot turn/move, so neither can the plane.

Paradox...

Go hop in your time machine and kill your grandfather before your father was born if you don't beleive me.

Here I took care of it for you:

The plane isn't a Harrier by chance is it? :lol:

And the plane can take off if there is a headwind greater than or equal to it's takeoff speed.

The only thing I can possibly think of that you are trying to say is that this:

"exactly match the speed of the wheels"

... doesn't refer to the speed of the surface of the wheel/conveyor belt, but the rotational speed. Is this correct?

(It doesn't matter anyway, my plane has huge wheels, their circumference is the same as the circumference of the conveyor belt, so it can still take off!)

you mean headwind + groundspeed (also known as airspeed)

Cody Wins... A VTOL is the only type of plane that makes this a non-paradox.

Yah, and I'm glad I got here late...

lmao, see now you get it. Nice balance on that plane there, sitting on one wheel and all.

Yes Mike, rotational speed. No one measures wheel speed as the speed of the aircraft with respect to the ground. It doesn't matter how big your belt is.

Huh? Well there is no groundspeed, but yah, I guess. I know jack about airplanes.

Sweet, I knew all that late night GTA Vice City would pay off someday. :lol:

Says an american ... ZING!

Actually if the belt and the wheels are the same circumference then they can rotate at the same speed without sliding. Here is a scale diagram to show what I mean:

The size of the wheels doesn't matter.

Ya but you would still be sitting in one place.

OMG, you are such an ass...hahahaha...That killed me. :lol:

You're right. Its the motion of the ocean.

That's just what girls say when the only thing they can stroke without laughing is your ego.

JC,

How can a harrier take off then? It too essentially has a frictionless bottem.

The reason, in my mind, a harrier can take off is that it requires zero latteral motion and therfore doesn't need the landing gear wheels to roll. This is also the reason I said a normal airplane can take off if the headwind is equal to or greater than the [airspeed] the plane requires to lift off.

Same reason a rocket does, lots of vertical thrust.

The version of the question in that thread is the correct version that actually does have a solution.

NASIOC = 16 pages
SECCS = 3 pages

hmmm. . .

Ya well half of us are engineers and one of us is an airplane designer. :p

It might have somthing to do with number of members each forum has... :P

and one of us is an engineer who is extremely bad at physics.

/tries not to look at self in mirror

Do I get a cookie for saying this first? (As far as I know; I only read the first page of the nabisco thread)

What kind of cookie would you prefer?

Does someone want to figure out the ratio of registered members to pages or posts in the respective threads? :lol:

I am most certainly not an engineer, hence my absence from the technical parts of the discussion :oops:

makes sense to me: plane not moving, air not flowing over wings, no lift, no flight.

the tires could be going as fast as you could imagine, and with no air over the wings for lift, the thing won't leave the ground.

(scratches head)

I think the general idea that our aerospace engineers here are trying to get at is that there's really no way a conveyor belt could stop a plane from moving, since a plane uses thrust from the turbines to move, not rotation of the wheels. The real confusion is coming from the poor wording of the problem. The idea is improbable in the first place. :P

Now, if a Subaru was on a conveyor belt. . . :lol:

Me for the win - post #6.

Here we go again ;)

http://www.i-club.com/forums/showthread.php?t=124084

Blame Ed :p

Oh my god. People cannot think! I couldn't get past the second page.

Ouch!

lamo air speed =0 of the needed 150. no take off. period. ;) easy one (course i've taken hang gliding lessons)

assume the needed Air wing speed for take off is 150 .

the aircraft engine sends thrust backwards , this pushes the air plane forwards.
as the plane starts to move forward (1 mph) the weight of the plane still bares down on the tires, the friction between the conveyor belt and the tires is great or than the friction of the wheel bearing (assuming no brakes are applied) the wheel rotates . the rotation of the wheel triggers the conveyor belt to move backwards at 1mph. thrust is still applied so the plane again moves forward and repeat.

with a jet engine there is not a great deal of air flow Over the wings by the jet engine alone, wings produce no lift . you've just created a very Inificient fan.

If its a propeller in front of the wings you will have air flow over the wings and create lift and you will take off with a ground speed of zero if you can manage to get the air moving fast enough around your wings.
so it should depend on engine placement.

also by exact definition of the question. if you locked your tires up, and the trust of your engine was enough to overcome the friction of the tires(lockedup) you'de slide them (not rotate) and the convyer belt wouldn't start up... ;)

(please at least post back the correct answer for the thread is locked )

Please lock this thread and let it die...

:?:

I'm almost tempted to lock all the old threads now...

FTW

Loud Noises!!!

it shouldn't be able to take off.... i hated physics by the way.

Why are we on this again?


i just got a nose bleed...

HOLY JESUS PEOPLE.

As originally written the question has no solution, there is a logical block in the wording.

As it should have been written, the plane will take off, with a wheel speed twice that of the airspeed.

Please read the thread before restarting this nightmare of an argument.

I don't know why we're yelling!

:lol:

We can't hear each other over the rod knock from your car!

my bad. lets lock the search button ...

Ooooh. You cut me deep on that one.

I was gone somewhere when this discussion was taking place. Otherwise, I would've put my simplistic answer as such

For every action there is an equal and opposite reaction.

Since an airplane, by our typical definition of terms, is assuming the reaction is a stable ground, no, the plane will not take off on a conveyor belt.

--> this person has never taken physics, but remembers stupid memory joggers.

T'was a good discussion all over the place anyway.