Riddle Me This.....Before My Brain Implodes!

[ElectricSheep]

ROFL

If the thrust force of the plane's engines is greater than the opposing dynamic friction of the wheels on the conveyor tarmac, then the plane will roll forward relative to the conveyor's superstructure regardless of the conveyor's speed.

Quite. I would argue that any opposing dynamic friction of the wheels on the conveyor tarmac is insignificant compared to the thrust of the engines, and thus even in a closed system there is till no force to counteract the force of thrust acting on the plane. The plane will move forward.

Of course, this means that the tires will move forward as well (as they are fixed to the plane). But, in order for the tires to move forward, they must have some relative difference in 'velocity' (sure, its rotational) compared to the linear velocity of the treadmill. But this magical treadmill will instantly match any velocity the tires have...

So what would really happen?

I argue that as soon as you flip the switch on the engines, both the treadmill and the tires will accelerate to infinity almost instantly, until they both explode in a gigantic violent fireball that is visible from space. The plane is destroyed in the carnage and is unable to take off.

 

[Airmoran]

Only ones where people don't change their opinion to match that of everyone else once the thread has been figured out

Hey, I admitted that I was fooled and tricked. Just in an implicit manner.

 

[Sir_Brizz]

Hey, I admitted that I was fooled and tricked. Just in an implicit manner.

don't forget that I was on your side at first as well

 

[Enfyrneaux]

I argue that as soon as you flip the switch on the engines, both the treadmill and the tires will accelerate to infinity almost instantly, until they both explode in a gigantic violent fireball that is visible from space. The plane is destroyed in the carnage and is unable to take off.

If I were the pilot, I would pitch the stick forward into the bumpers just to be an ass.

 

[klasnic]

Bah of course it can take off it's a Harrier jump jet

 

[K]

OK let me try to explain how the wheels have no bering on the equation.
You know what this is right:

If this vehicle was on a conveyor "that would move at the same speed in the opposite direction", Would the vehicle move forward? Hell yes it would.


This is a great thread. It is an interesting question indeed.

 

[Bean 3:16]

1113213211

Best way to work it out is to say it out loud i find.

Ha, now it makes sense

 

[Sir_Brizz]

No, because it has no method of eating the reversed directional force. In other words, it would just sit on the conveyor belt as it moved, or flip over. Either way it would be entertaining to see how stupid it would look.

 

[klasnic]

If the pilot blows straight out the window does he actually not blow at all because of the opposite force?

 

[K]

Hmmm, a Hovercraft has air being pushed towards the ground to eliminate the force of the ground against the craft.

On an airplane the wheels are always touching the ground and there is nothing to counter the force the ground puts on the wheels cause of the weight of the plane. So the Plane would stand still? If it moved it would not be far because the conveyor would adjust to the movement and extract the opposite force on the weight bearing wheels. So you increase throttle on the propulsion. So in turn the conveyor speeds up to match. This i assume would be instantaneous so , the plane would again not move very much, maybe a few feet. Hardly enough to have enough pressure on the wings to lift off.

If the plane was suspended from a ceiling by string. It would lurch forward but it would not take off either. The weight of the plane cannot be overcome by the propulsion unless the movement was initiated sufficiently. This is only accomplished with the help from inertia.

in·er·tia Audio pronunciation of "inertia" ( P ) Pronunciation Key (-nûrsh)
n.

1. Physics. The tendency of a body to resist acceleration; the tendency of a body at rest to remain at rest or of a body in straight line motion to stay in motion in a straight line unless acted on by an outside force.
2. Resistance or disinclination to motion, action, or change: the inertia of an entrenched bureaucracy.

Energy built up from constant movement. If the plane starts rolling on a normal runway , It takes more energy to start the role then it does to keep it rolling. If the energy to get the role started was immediately countered on a conveyor belt then the craft will not move unless the propulsion is greater then the force of the weight of the plane on the ground. The propulsion must also be faster at increasing then the conveyor is at compensating. There is probly a ratio some one could through in there. So there is information missing from the equation. The question is unanswerable as is.

Or the answer is "yes , if . . .such condition and such condition are met by the propulsion . . . . ."

 

[Angel_Mapper]

Yeah, it's a bit unclear as to wether it's talking about the plane's velocity relative to Earth or to the conveyor belt.

 

[anaemic]

look, if this was a car, it would go nowhere, because the wheels play a vital part in the forward thrust of a car.
an aeroplane moves forwards by the force of displacing such a large quantity of air through its engines, when a plane is traveling at a speed it is doing so relative to the air around it, not to the ground below.

the conveyor belt can spin all freaking day but as long as the engines are on then all that force will do is spin the planes wheels twice as fast compared to it being on stationary ground for takeoff.



now stop bumping this goddamn thread > : (

 

[ElectricSheep]

I'm curious to know where people think this 'force of ground against the aircraft' is coming from, and how it is operating?

Draw the system. Document all forces involved and their vectors. Please tell me which force(s) acts to oppose the force of thrust generated by the engine?

Is it the rolling friction acting on the wheels? This is a force of static friction, and is a constant involving a coefficient (less than 1) and the mass of the aircraft. Better yet, what direction is that force operating in?

If you anchor the plane with a string (or tether of some kind), you will introduce a tensile force which directly opposes the force of thrust. That is, to the tolerances of the tether.

 

[Otej]

The ground's force against the plane's mass is at 90 degrees to the direction of movement and as such does not factor. WAS MY GIF NOT GOOD ENOUGH FOR YOU?????////????????//????

 

[B]

Edit: Yes it can

 

[sid]

look, if this was a car, it would go nowhere, because the wheels play a vital part in the forward thrust of a car.
an aeroplane moves forwards by the force of displacing such a large quantity of air through its engines, when a plane is traveling at a speed it is doing so relative to the air around it, not to the ground below.

the conveyor belt can spin all freaking day but as long as the engines are on then all that force will do is spin the planes wheels twice as fast compared to it being on stationary ground for takeoff.

Hmm youre pretty much right. I was going wrong with the wheels ......its pretty clear now

A car is powered by wheels connected directly by an axle to the car's engine so the car actually wil never change its position if on a conveyer but a plane is powered by its engines and wheels are not even close to being connected to the engines so the although the plane will move and probably take off the car will stay stationary.

It kinda reminds of those battery powered toy cars which if you try to push ahead pretty much never change their pace due to their battery-powered wheels not allowing them to go faster.

Sorry for all the posts before and thanks to anaemic and bob-the-wise for clearing this fukin question which made me sleep at 5 in the AM.

 

[Enfyrneaux]

The ground's force against the plane's mass is at 90 degrees to the direction of movement and as such does not factor. WAS MY GIF NOT GOOD ENOUGH FOR YOU?????////????????//????

Use terms like "non-static dynamic friction", "directional magnitude acceleration vector" and "antiparallel perpendicular normal force"; the bumpers will think you're some kind of postdoc physics guru

EDIT - I forgot "nano". You must include "nano", without it you might as well have anime with no blue hair.

 

[Zarkazm]

The "lead pants" thing is a straight-up understanding of physics. This plane thing is a riddle intended to fool people into thinking it's a simple matter of aerodynamics. asdlfkjas;ldkfjasldjfasdf.

Except that the most basic understanding of aerodynamics would solve this riddle, as Namu demonstrated.
The point is that both are going against conventional wisdom. People are fooled into confusing the situation with a similar one here. In the case of gravity, they tend to reiterate punch lines they've heard without really understanding the physics behind it. The result is the same really.

 

[namu]

Ok, since the conveyor belt speed is equal to the plane speed, we can assume that with no outside forces involved the system is in equilibirum in reference to the earth. In other words, the velocity is equal to zero.

This sentence makes no sense. What forces are you talking about ? Belt applies no force to the plane beyond the negligible friction on the wheels.

The plane is moving forward relative to the world, the belt moves the same speed but backwards relative to the world, so the plane moves twice as fast relative to the belt. Clearer now ?

 

[Deathmaker]

I say we kill the thread starter for beginning the mess.

Agreed

Yeah, burn him! That Deathmaker is a total sh|t stirring bugger!

I've just read all the replies & I've not laughed so much here in a long time, some great replies. It really reminds me of the "Swallow carrying a coconut" Holy Grail scene. Thanks chaps! :tup:

Oh, I found this too: