Plane

[Arthur Wedge]

Tell us what you think, will it take off.

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

 

[Deleted member 35927]

Great. You've both misunderstood the puzzle. The wheels and conveyor belt are red herrings. They represent an invisible force that maintains zero ground speed as long as the plane is in contact with the ground.
The thrust of the engines provides enough airspeed washing across the wings to achieve takeoff while stationary relative to the Earth, theoretically. It's that simple.

How can the treadmill offer the opposing force against the jet engines via the free spinning wheels.
You have gone off on some strange tangent.

 

[RichA]

How can the treadmill offer the opposing force against the jet engines via the free spinning wheels.
You have gone off on some strange tangent.

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.

 

[Deleted member 35927]

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.

What ? Sorry you've lost me know. If you physically hold the plane still it won't take off .

 

[Deleted member 35927]

Surely need to sort out the tree falling in a forest issue first

Thats philosophy, if you'll pardon the pun .

 

[Lord Tyrion]

This really is passing my by, quite happily I must add, but one thing that keeps coming up that confuses me is the wheels aspect. How about the plane is no longer a 747, or equivalent, but a sea plane. The wheels then are no longer in the equation.

I shall now disappear off again

 

[RichA]

What ? Sorry you've lost me know. If you physically hold the plane still it won't take off .

The superheroes are only preventing horizontal movement. As the plane leaves the ground they let it go.

 

[RichA]

This really is passing my by, quite happily I must add, but one thing that keeps coming up that confuses me is the wheels aspect. How about the plane is no longer a 747, or equivalent, but a sea plane. The wheels then are no longer in the equation.

I shall now disappear off again

With or against the tide?

 

[Voyager EMH]

Great. You've both misunderstood the puzzle. The wheels and conveyor belt are red herrings. They represent an invisible force that maintains zero ground speed as long as the plane is in contact with the ground.
The thrust of the engines provides enough airspeed washing across the wings to achieve takeoff while stationary relative to the Earth, theoretically. It's that simple.

I think it is that the conveyor does not impart enough backward force to the wheels to counteract the force of the engines.
The engines are very powerful and cause the plane to move forwards through the air relative to the earth.
The conveyor does not, and cannot, impart enough force to halt or even lessen that forward force through the air relative to the earth.
The plane moves across the conveyor as if the conveyor is still.

This does require that the wheels are free to rotate at a "whatever" necessary rate and cannot themselves restrict the speed of the plane. I think this is the theoretical case.

 

[Lord Tyrion]

With or against the tide?

I thought it was on a treadmill .

There are reasons I don't get involved in physics related discussions (the main 2 being I neither understand nor care ) It's been fun seeing the back and forth and the brains over heating though.

 

[Voyager EMH]

This really is passing my by, quite happily I must add, but one thing that keeps coming up that confuses me is the wheels aspect. How about the plane is no longer a 747, or equivalent, but a sea plane. The wheels then are no longer in the equation.

I shall now disappear off again

Ah, what if the seaplane is on a river.
Will it take off easily downstream, but find it much harder, or impossible, to do upstream?

(I've never been water-skiing, because I've never found a lake with a decent slope.)

 

[Bunkermagnet]

I think it is that the conveyor does not impart enough backward force to the wheels to counteract the force of the engines.
The engines are very powerful and cause the plane to move forwards through the air relative to the earth.
The conveyor does not, and cannot, impart enough force to halt or even lessen that forward force through the air relative to the earth.
The plane moves across the conveyor as if the conveyor is still.

This does require that the wheels are free to rotate at a "whatever" necessary rate and cannot themselves restrict the speed of the plane. I think this is the theoretical case.

The OP says the conveyor belt is programmed to match the speed of the wheels. So unless the 747 is hovering, gravity would dictate the imdercarriage is in contact with the conveyor belt so any forward movement of the plane through the thrust of the engines would be countered by the conveyor belt moving in the opposoite direction so the plance would stand still effectively.
Ultimately this is one of those pointless FB conundrums that can never be proved and everyone can argue away all day.

 

[Deleted member 35927]

The OP says the conveyor belt is programmed to match the speed of the wheels. So unless the 747 is hovering, gravity would dictate the imdercarriage is in contact with the conveyor belt so any forward movement of the plane through the thrust of the engines would be countered by the conveyor belt moving in the opposoite direction so the plance would stand still effectively.
Ultimately this is one of those pointless FB conundrums that can never be proved and everyone can argue away all day.

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.

 

[Arthur Wedge]

I think it is that the conveyor does not impart enough backward force to the wheels to counteract the force of the engines.
The engines are very powerful and cause the plane to move forwards through the air relative to the earth.
The conveyor does not, and cannot, impart enough force to halt or even lessen that forward force through the air relative to the earth.
The plane moves across the conveyor as if the conveyor is still.

This does require that the wheels are free to rotate at a "whatever" necessary rate and cannot themselves restrict the speed of the plane. I think this is the theoretical case.

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

 

[SwingsitlikeHogan]

Without reading through 16 pages…a related question. If the aircraft is flying at Xmph and suddenly the airflow within which the aircraft is flying turns to an exact following wind so that there is precisely zero ‘headwind’ does the aircraft fall out of the sky? And if not why do aircraft have a minimum speed beneath which the aircraft will ‘stall’…and if it does what then happens?

 

[Deleted member 35927]

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

No it does not. But thats the error some are making.

 

[Arthur Wedge]

No it does not. But thats the error some are making.

Plane with no wheels

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

 

[Deleted member 35927]

Plane with no wheels

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

Not enough information.

 

[SwingsitlikeHogan]

Plane with no wheels

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

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.

 

[Arthur Wedge]

Not enough information.

What other information do you need ?