Plane

[Bunkermagnet]

You're making the same mistake as others in assuming the wheels offer some sort or drive , they don't they simply spin freely.
Read newtons 2nd law and then explain how the conveyor and wheels can provide the required opposing force to stop the plane moving forward. It's science fact my friend.

Of course the try to rotate. Unless the brakes are on, the weight of the plane will mean they rotate with the plane which is countered by the conveyor belt.
Anyway, it's as I said previous. There can never be proof it will happen either way.

 

[Arthur Wedge]

If we consider the example of thr plane being very light, offering minimal friction to the ground, then the answer becomes obviously yes - after all that’s what skids do.

How about a good old jumbo 747

Would it drag along the runway until there is enough airspeed

 

[RichA]

You're making the same mistake as others in assuming the wheels offer some sort or drive , they don't they simply spin freely.
Read newtons 2nd law and then explain how the conveyor and wheels can provide the required opposing force to stop the plane moving forward. It's science fact my friend.

He isn't. The opposing force is the wind generated by the engines, which eventually provides enough airspeed for a stationary liftoff.
You're misunderstanding what the wheels do or don't do. Yes, they are passive but as long as the plane is in contact with the ground and the treadmill perfectly matches their rotation then the plane is standing still.
Done by your own puzzle, unfortunately.

 

[Swango1980]

Theoretically then if there is enough thrust to create the air speed required ( relative to the “treadmill” speed ) then a 747 may potentially rise into the air

You genuinely believe that the power of a jet engine cannot overcome the speed of a treadmill?

So, if you have enough thrust to accelerate the mass Boeing 747 to 180mph, a treadmill would overcome this thrust if it was moving at 180mph in the opposite direction. Please think before you commit to giving your answer

 

[Swango1980]

Forget the treadmill. Forget the wheels. Imagine Superman and Thor are holding the landing gear and preventing any forward movement as long as the plane is in contact with the ground.
The thrust of the jets or props of any plane creates enough air movement around the wings for takeoff airspeed.

If that theory worked, then an aircraft carrier wouldn't need any runway. If could just clamp the plane, let the pilot start the engines and let go when the plane lifted off.

 

[Arthur Wedge]

You genuinely believe that the power of a jet engine cannot overcome the speed of a treadmill?

So, if you have enough thrust to accelerate the mass Boeing 747 to 180mph, a treadmill would overcome this thrust if it was moving at 180mph in the opposite direction. Please think before you commit to giving your answer

When did I say that

 

[RichA]

Plane with no wheels

Just on stand - engines go on - will it take off

Yes. Which is why a light aircraft that only needs 25mph of airspeed to take off can theoretically takeoff from stationary into a 25mph breeze.

 

[Deleted member 35927]

He isn't. The opposing force is the wind generated by the engines, which eventually provides enough airspeed for a stationary liftoff.
You're misunderstanding what the wheels do or don't do. Yes, they are passive but as long as the plane is in contact with the ground and the treadmill perfectly matches their rotation then the plane is standing still.
Done by your own puzzle, unfortunately.

No you've fallen down some rabbit hole of strangeness . I don't even know where to begin to pull you out.

 

[RichA]

If that theory worked, then an aircraft carrier wouldn't need any runway. If could just clamp the plane, let the pilot start the engines and let go when the plane lifted off.

Theoretically yep, but not practically possible and landing would be tricky.
They're heavy so they need to guarantee the speed using a runway.
Light aircraft however...

 

[Swango1980]

When did I say that

Answer the second question to help me understand what it is you are saying please

 

[Swango1980]

Theoretically yep, but not practically possible and landing would be tricky.
They're heavy so they need to guarantee the speed using a runway.
Light aircraft however...

Are you telling us in that video that the aircraft is taking off in calm conditions, and it is simply the engines creating the flow over the wings and lift? Or, is it possible it is a windy day in that video?

 

[Arthur Wedge]

Answer the second question to help me understand what it is you are saying please

Think it’s time for a little step back please

This is my opinion on the matter as already stated

“Theoretically then if there is enough thrust to create the air speed required ( relative to the “treadmill” speed ) then a 747 may potentially rise into the air”

 

[Swango1980]

Think it’s time for a little step back please

This is my opinion on the matter as already stated

“Theoretically then if there is enough thrust to create the air speed required ( relative to the “treadmill” speed ) then a 747 may potentially rise into the air”

So, it is true. If there is enough thrust to accelerate a jumbo jet 180mph down a static runway, you believe that if it is on a treadmill that is moving 180mph in the opposite direction you believe that will cancel out the thrust provided by the jet engines, and remain static relative to someone standing next to runway, and thus not be moving forwards through air.

Thanks for confirming, as I just wanted to see how your logic works and how it doesn't work.

 

[RichA]

Are you telling us in that video that the aircraft is taking off in calm conditions, and it is simply the engines creating the flow over the wings and lift? Or, is it possible it is a windy day in that video?

No, I didn't say that.
Shortly before posting that vid I did say, "... a light aircraft that only needs 25mph of airspeed to take off can theoretically takeoff from stationary into a 25mph breeze."
It's just random YT vid to illustrate a point.

 

[Arthur Wedge]

Theoretically yep, but not practically possible and landing would be tricky.
They're heavy so they need to guarantee the speed using a runway.
Light aircraft however...

Just use a F35

 

[Arthur Wedge]

So, it is true. If there is enough thrust to accelerate a jumbo jet 180mph down a static runway, you believe that if it is on a treadmill that is moving 180mph in the opposite direction you believe that will cancel out the thrust provided by the jet engines, and remain static relative to someone standing next to runway, and thus not be moving forwards through air.

Thanks for confirming, as I just wanted to see how your logic works and how it doesn't work.

It is amazing how you come to a completely different conclusion on what I “believe”


Always remember - it’s theoretical

 

[Voyager EMH]

Just one thing

With the “riddle” or whatever it’s caused saying that the “treadmill” will match the wheels speed going in the opposite directions does that then mean the plane stands still and airspeed isnt generated to then allow the plane to rise

The engines provide the forward movement with the “wheels” allow the plane to move forward but then the treadmill counters that

The OP says "...is programmed to" not "...will".

It might have been a Fujitsu.

Don't take that too seriously, but many a true word etc.

I'm on a travellator moving at 5mph. My friend is beside me, not on the travellator, on rollerskates, I have my hand behind his back and he rolls along next to me.
He is about to go onto a similar travellator, but one that moves 5mph in the opposite direction. There are no other people on the travellators.

A. I break my arm or I am knocked over.
B. I am able to keep him next to me, but only if I am able to double the power of my push through muscular effort to "counteract" his travellator.

C. He moves along next to me, I make no extra effort, his wheels rotate as they did before relative to the surrounding non-travellator surface, but faster from the point of view of their axles.

D. Something other than A, B or C.

Can it be possible that the same force propels my friend whether he is on static ground or on a travellator moving against him with his wheels free to rotate.

What if the force was not my hand, but he was a sail in the wind?
Can the wind still move him at 5mph once he mounts the travellator or are the wheels prevented (somehow) from increasing their rotation about their axles?

 

[Arthur Wedge]

The OP says "...is programmed to" not "...will".

It might have been a Fujitsu.

Don't take that too seriously, but many a true word etc.

I'm on a travellator moving at 5mph. My friend is beside me, not on the travellator, on rollerskates, I have my hand behind his back and he rolls along next to me.
He is about to go onto a similar travellator, but one that moves 5mph in the opposite direction. There are no other people on the travellators.

A. I break my arm or I am knocked over.
B. I am able to keep him next to me, but only if I am able to double the power of my push through muscular effort to "counteract" his travellator.

C. He moves along next to me, I make no extra effort, his wheels rotate as they did before relative to the surrounding non-travellator surface, but faster from the point of view of their axles.

D. Something other than A, B or C.

Can it be possible that the same force propels my friend whether he is on static ground or on a travellator moving against him with his wheels free to rotate.

What if the force was not my hand, but he was a sail in the wind?
Can the wind still move him at 5mph once he mounts the travellator or are the wheels prevented (somehow) from increasing their rotation about their axles?

It’s far too early on a Monday

But you’re not wrong about Fujitsu

There are lots of these types of “scenarios” that require lots of theoretical thinking and it’s certainly thought provoking

 

[Slab]

I can see why it would/could/might take off… and I can see why it won’t/can’t/might not take off

Unless you plan to build it then its cool to mull it over… for about 2 minutes, max

 

[Swango1980]

It is amazing how you come to a completely different conclusion on what I “believe”


Always remember - it’s theoretical

It is probably because you lack clarity, and I don't know if you are intentionally doing so? Because, I'm not sure why you are comparing the force of the engines thrust relative to the treadmill speed? The treadmill speed is irrelevant to the forward motion of the plane.

It may be theoretical as nobody has designed such a treadmill. But, it isn't something where the answer is unknown if it was tried, because the mathematical and physical theory is sound. There would be no point in designing a system, because the answer is known.

If a software engineer was asked to developed such a system to operate the treadmill, they would soon realise it is impossible to achieve in practice. They'd end up in an infinite loop. The speed of the wheels is passive, thus an output, and a function of the speed of the plane caused by thrust and the speed of the runway. A programmer would need to set the treadmill speed to an output, to match the speed of the wheels in the opposite direction. So, as engines get plane moving, the speed of the wheels would send an input to the treadmill to move in opposite direction. But, once that is converted into an output in actually moving the treadmill, that is a change in the input that the wheel speed is dependent on. So, the wheels get even quicker. The software will always be reacting to ever increasing inputs from the wheels, but never be able to catch up.

The plane would continue to merrily accelerate down the runway, because it doesn't care one bit what the wheels are doing. It isn't a car. meanwhile the wheels and treadmill would be continually speed up as they are dependent on each other. As speeds get crazy high, the software may crash, mechanics of wheels may get destroyed as they can't cope, or the frictional force exceeded between wheels and ground that they end up just skidding as they grip and re-grip continually. The only way the plane will stop moving forward is if the wheels get destroyed and it crashes