John, if you're still confused about why it won't move then go back and read the first 25 pages of this thread. Through the use of simple physics and mathematics, I proved over and over again...once and for all...that the plane will never move.

I realize it is hard to grasp because it doesn't seem logical. It doesn't seem logical because it's NOT logical. You can think Geico for that. He's the one that thought this whole thing up...and we KNOW he is logically impaired (just like the 32 people who think the plane will move).

 

First off the plane would fly... because there is no way for the conveyer belt to match the speed of the wheels on the plane. Anyone basing logic on that case... well they obviously didn’t pass their physics class. Because unless this experiment it done in a vacuumed environment the Plane will move forward. Now if there were some device that could do this as soon as the plane were to move forward the wheels would be traveling at infinite mph.. the wind created by a belt traveling at infinite mph would create enough lift for the plane to take off. The only speed that the belt could do the same as the wheels on the plane would be 0. or infinite.

So your answer Is. NO Solution
heres one for you.... 10/0=???

Oh yea... lets say its a Harrier jet... its taking off no problem.
justin

 

Yeah, what he said. The wheels have nothing to do with takeoff. They are not drive wheels, they are simply rollers. Come on people think it all the way through.

 

The answer would be no solution if it wasn't for the force of friction in the axle that eventually equals the thrust of the engines and therefore stops acceleration of the wheels and conveyer belt.

Without that friction, however, the answer would be "No Solution".

But if you assume that the wheels will take any force at all to spin, then the answer is "No, the plane won't take off".

The answer would only "Yes, the plane will take off" if you were in the real world, which is of course irrevelant.

 

the plane is not moving, how can it fly?

 

the plane will have lost traction long before the trust of the engines have been overcome.

the wheels would act like skies on the conveyer belt. And since their was nothing stated about traction in the original question. The plane will take off ( depending on the plane)
and the lift provided air flow from the Belt. Would be enough to provide lift for the air plane to get off the ground.

 

The reason the answer is NO SOLUTION is Because the belt can Never match the Speed of the wheel.
Therefore rendering the equation unsolvable.

 

Yeah, YOU proved it

One... Last... Post...

The plane is sitting there. To humor John Halter, we'll assume its out of fuel and hooked to a CTD trying to pull it forward. The driver puts the truck in gear and lets off the brake (or lets out the clutch, in the case of a manual). The plane "tries" to creep forward, but because ground speed (and therefore air speed, because there's no wind) is equal to the wheel speed minus the conveyor speed, it goes nowhere. If you don't understand this part, lets look at a normal take-off.

This all assumes the plane is on the ground and there is a frictional force between the wheel and the ground greater than rolling resistance of the wheel.

A plane is rolling down a runway at a constant speed. Lets say the plane moves at 100 MPH. How fast will a point on the outside of a wheel be going? Then speed the plane up again to 120 MPH. How fast will a point on the outside of a wheel be going? It will be traveling at the plane's ground speed, 120 MPH. Plane speed relative to the ground = wheel speed-the speed of the surface the plane sits on relative to the ground. In our regular take off, plane speed (120) = wheel speed (120) - surface speed (0). Now what happens when you slow the wheels down with a brake? The plane speed decreases, provided the friction between the wheels and the surface is greater than the (now greater) rolling resistance. Wheel speed is NOT independent of plane speed while the plane is on the ground.

Whew... Now that I'm done explaining that, we can apply it to the conveyor situation.
I'll set up some variables here:
y = plane speed
x = wheel speed
z = surface speed relative to the ground

y (plane speed) = x (wheel speed) - z (surface speed)

now, x=z because in the original problem, conveyor speed matches wheel speed, so x can be substituted for z.
so,

y=x-x Always equal to zero.

So no matter how hard the CTD tries, no matter how many tranny's it toasts, no matter how many clutches it fries, no matter how many tires it roasts, no matter how many driveline parts it mangles, the tires (and conveyor) will speed up indefinitely until rolling resistance=thrust.

Now I really am going to quit posting here. I have explained it to the best of my abilities, and it is up to people's minds from here on out.

 

Upon further review, the plane will not fly. Period. I started a long post as to why it would fly and by explaining it I realized that it wouldn't. I also asked about 40 other aviators. Most at first thought it would fly, but then we realized we were wrong .

Now that I have cleared it up, how about a new riddle?

 

People. You are assuming 100% traction. Not in the original question. And since the belt cannot actually match the speed of the wheel on the plane in opposite. Traction will be lost. The real question is can a plane take off with the wheels all locked???
In order the for the wheel speed to match the speed of the jet and the belt must be 0 there can be no acceleration from either In Relation to a stationary object. And even in that case a harrier jet can still take off. So yes there is a plane that can take off from a conveyer belt that can match wheel speed.

The real solution is NO SOLUTION Because Physics says its imposable for something to acalerate on a conveyerbelt moving the opposite speed.

agian. you are asking me to divide by 0. give me the awnser to 5 divided by 0 and i will give you the awnser to this....

 

I dont know if anyone figured this out yet and I am not going to read all 29 pages to find out, but the conveyer belt and wheel speed dont matter. the foward motion of the plane is from thrust of the engines thru the air. the wheels are free spinning and not connected to any drive components. the thrust from the engine will overcome any speed of the conveyer belt and the plane will takeoff in the same amount of distance as on a runway. (provided the wheels dont burst in to flames from spinning exponential RPM's from running on the conveyer) Kind of like a plane with snow skies, no traction on the snow or ice just like the wheels that spin from the motion of the conveyer. But the plane on the ice still takes off.

 

I love this place.

29 pages of bickering, yet no one has stooped to name calling or flaring tempers

I challenge anyone to fine another discussion board where it could have gone on this long and stayed civil.
That's why I'm voting to keep it open, just to prove that it can be done.

Oh, and if there is no solution, but the question was "will the plane fly" or "will the plane not fly", then it won't fly.

phox

 

I can not believe that so may people think this plane can not move . I will try one last time , if you hook a rope to the plane stand beside the conveyor and pull it with a Cummins it will move forward and the conveyor will match the wheel speed .The Cummins is not on the conveyor our it would not move . The Cummins has nothing to do with the conveyor and either does the prop . The prop is not connected to the tires if the plane is moving 10 mph and conveyor is moving 10 mph in the other direction how fast are the tires moving ? The answer would be 20 mph and at lift off speed at around 65 in my plane the tires would be going 130 . The plane is going 65 the conveyor is going 65 and the tires would be going 130 .

 

The plane will move, no doubt about that,
it just won't move fast enough to create lift and therefore take off.


phox

 

So tire speed would be twice what the conveyor speed is, is that what you're saying? The original question states that conveyor speed is always equal to wheel speed, not plane speed.

Imagine that, I posted again, even after saying I wouldnt