conveyor belt and plane answered at last ??

[doitall]

It doesn't matter whether the wheels are free wheeling or being driven by a tank.

The plane is fixed to the wheels, and for the plane to reach 85knots the wheels have to turn or the plane ain't going any where.

Now read the question again, especially the red bit.

 

[securespark]

OK. The plane is fixed to the wheels, you say. How are they fixed?

How does the relationship between the wheels and belt stop the plane's engine applying sufficient thrust to drive the plane forwards?

 

[doitall]

OK. The plane is fixed to the wheels, you say. How are they fixed?

How does the relationship between the wheels and belt stop the plane's engine applying sufficient thrust to drive the plane forwards?

It doesn't stop the plane driving forward, but in order to do so the wheels have to travel faster than the belt.

The wheels are attached to the plane, for the plane to move the wheels have to turn.

 

[matt1e]

As the belt picks up speed the plane must increase the engine speed to stop it going backward, in the meantime the belt is turning the wheels at the same speed.

We now have a stalemate, the conveyor is trying to take the plane backward, and the propeller is trying to move the plane forward, we have equilibrium.

Plane still ain't taking off

No mate you have the opposite, you have apposing force which can only ever result in motion relative to each other

OK. The plane is fixed to the wheels, you say. How are they fixed?

How does the relationship between the wheels and belt stop the plane's engine applying sufficient thrust to drive the plane forwards?

It doesn't stop the plane driving forward, but in order to do so the wheels have to travel faster than the belt.

The wheels are attached to the plane, for the plane to move the wheels have to turn.

No whilst they are in contact with each other then one can never go faster than the other, ever It defies physics they will always be at the same speed

Think of the wheels as indicators of apposing force
Equilibrium results in the wheels not moving

I'll try one last time
The earth is rotating on its axis at a speed of around about 1000 MPH at the equator,it rotates toward the east
So a plane sitting on a east/west facing runway located at the equator is either traveling forward at a 1000 mph along with the runway or traveling backwards at 1000 mph along with the runway
Of course no motion is perceived as its in equilibrium with the ground , indicated by the lack of wheel movement
So how can a plane take off facing either eastbound or westbound?
Easy it just has to go off in either direction with enough apposing force to interact with the air around it that is to cause lift
So head off west ward at around 85 knots so you are going about 100mph slower than the rest of the earth and you will take off
Alternatively head off west ward at around 85 knots so you are going about 100mph faster than the rest of the earth and you will also take off
In either scenario right up to the moment the plane lifts off, the wheel surface will be at the same speed as the ground but in the opposite direction
Now sit the plane on a conveyor belt that is in contact with the earth
Along side it sit a car on another conveyor that also tracks the wheel motion
In the case of the car it will sit stationary in space and there is nothing the driver can do about it as it is the engine transfering all its power to the wheel that is trying to propel the car, so the conveyor can in turn apply a directly apposing force
The plane how ever is not propelling it's self via the wheels so the belt can't keep the plane stationary as it cant have any effect on the planes method of propulsion

 

[doitall]

Hold your horses.

The conveyor isn't in contact with the earth or it's not a conveyor.

That's the big failing with the myth busters.

Put a cloth on a table and yank it out from under the best china, does it all crash to the ground.

Now put the best china on a conveyor belt and start it up and see what happens.

For the plan to go forward the wheels have to turn to give it forward travel, for it to move along the conveyor it has to go faster than the conveyor belt, which means the wheels are now going faster than the belt. Not allowed.

the aircraft's wheels speed and tunes the speed of the conveyor belt to be exactly the same as the wheels

 

[AronSearle]

Sigh.

The wheels don't need to go faster than the conveyor belt for the plane to move forward, the belt can match it's speed backwards and the plane still goes forward.

The ball bearings have to go faster, but that is what they do.

http://en.wikipedia.org/wiki/Bearing_(mechanical)

You seem to just be defending an inane position on some poorly worded or bad interpretation of a basic question.

 

[matt1e]

Hold your horses.

The conveyor isn't in contact with the earth or it's not a conveyor.

Is this conveyor floating in mid air then?
It is in contact with the earth and has a movable surface called a belt

Put a cloth on a table and yank it out from under the best china, does it all crash to the ground.

Now put the best china on a conveyor belt and start it up and see what happens.

Irrelevant, and put anything on a conveyor and the same thing will happen
Unless the thing in question has its own method of propulsion

For the plan to go forward the wheels have to turn to give it forward travel, for it to move along the conveyor it has to go faster than the conveyor belt, which means the wheels are now going faster than the belt. Not allowed.

No, thats the case for a car etc
for the plane to go forward the wheels have to turn to allow it to travel forward there is a difference

the aircraft's wheels speed and tunes the speed of the conveyor belt to be exactly the same as the wheels

And that would stop a car traveling forward but not a plane as a planes wheels are freewheeling
Look
Take your average light aircraft 85 knots take off speed? That's roughly 100 mph, while its hurtling along the ground it will cause the wheel to rotate at a given rpm till it takes off, while it is in contact with the ground the wheel surface will be traveling along at the same speed as the ground in the oposite direction, it has to as they are touching
Put the plane on a conveyor belt whose rollers are the same diameter as the planes wheels and apply thrust then what will happen is the plane will hurtle down the conveyor which is by the way attached to the earth at exactly the same speed as if it were on the runway,
The conveyor belt reacting to the wheels will just make the wheels spin twice as fast as they normally would

 

[doitall]

It doesn't matter if it's poorly worded or bad interpretation to a basic question.

The question is, given the circumstances in the question will the plane take off.

If you sit a plane on a conveyor belt going at 100mph, the plane will also be going backwards at the same speed.

The plane starts up has to match 100mph to just hold in the same position.

To move against the belt it has to go faster, and if the plane goes faster so does the wheels thats fixed to the plane

 

[doitall]

matt1e

No difference between the car and the plane, they both have wheels and they both need to go round, the fact that one is free-wheeling is irrelevant, they are both recording a speed over the belt.

The plane is not in contact with the ground it's stood on a conveyor belt, the weight of the plane is on the conveyor not the ground, a big difference.

It doesn't matter how fast the wheels spin they are matching the conveyor.
So the plane cannot move forward, the faster it all goes the more trust is needed to stop it going backward.

 

[securespark]

According to the puzzle, the belt is going backwards at exactly the same speed of the plane.

However, that doesn't mean that backwards force is being transmitted to the plane.

The wheels have got a minimal friction and are freewheeling, therefore the plane can still move forwards with respect to the belt.

 

[securespark]

No difference between the car and the plane, they both have wheels and they both need to go round, the fact that one is free-wheeling is irrelevant, they are both recording a speed over the belt.

But there is a big difference: the car's wheels are driven by its engine, the plane's wheels are not.

 

[matt1e]

for the last time
it is impossible for the wheels to go at a different relative speed than the belt while they are touching ever whether the ground beneath it is moving or not
Why can't you see this?

And in your post above , the plane Does not have to match 100mph to keep stationary at all .this is where your thinking is going wrong, it only has to generate enough apposing force to counter the belt which considering that it has freewheeling wheels and a method of propulsion that interacts with the air not the ground or the belt it's on then it can achieve this easily

 

[AronSearle]

If you sit a plane on a conveyor belt going at 100mph, the plane will also be going backwards at the same speed.

The plane starts up has to match 100mph to just hold in the same position.

To move against the belt it has to go faster

What inane dribble is this?

You already have the plane moving backwards, you argue it has to move forwards to stay in place, but then you argue it cant move forwards.

Silly silly person.

 

[doitall]

matt1e

Whats impossible about it.

Any object would have to go faster than the belt to move forward in the opposite direction to the belts travel

My thinking is not going wrong.

The plane is stood on the conveyor going at 100mph and the wheels are not going round, to stop the backward trend the wheels have to start turning at the same speed as the belt it's stood on, the only way it can do that is apply thrust until all things are equal.

Now wind the conveyor up to 200mph, and the plane has to give it more thrust or start going backwards again.

 

[doitall]

What inane dribble is this?

You already have the plane moving backwards, you argue it has to move forwards to stay in place, but then you argue it cant move forwards.

Silly silly person.

Just demonstration the plane needs energy to stop it going backward, and the faster the conveyor the more energy it needs.

In real life I know the plane can move forward and take off, but not in the parameters of the question.