If an AIRPLANE is on a TREADMILL will it take off? (Physics)

[Steak_n_Taters]

Does it matter if the treadmill had its own motor and isn't being turned by the wheels of the plane? In for answers.

The assumption is the treadmill has a motor.

..wut............. Thrust's only purpose is to move a plane FORWARD THROUGH THE AIR TO GENERATE LIFT

Thrust doesn't lift a plane into the air....... the air pressure difference above and below a wing is what lifts a plane into the air.....we call this Lift.

ok I'm done ITT... ya'll hit your heads too hard

The above is correct (mostly - there are planes with thrust vectoring that lift off purely via thrust).

What you are wrong about is that the wheels would NOT stop the plane from moving forward. Forward motion gives you flow over the wings which gives you lift.

What part of this are you not getting?

[NoobGains23]

Your incorrect assumption is that the wheels are imparting a force on the plane, which they are not. The wheels will accommodate the treadmill speed + the rotational speed imparted by the plane moving forward.

Say the planes engines make the wheels turn at 15,000 RPM at half thrust (pulled that out of thin air, doesnt matter), and the treadmill also makes the wheels spin at the same RPM. Then the engines are put on full thrust, so the engines cause the wheels to spin at 25,000 RPM, the treadmill then matches this. To a person standing by the side of the treadmill, he sees a stationary plane with wheels spinning incredibly fast.
He can stand on the wing and light a cigarette.
No planes took off that day

[Gewicht]

You have absolutely no idea how a plane lifts off the ground. Thrust is not the only factor...... you need LIFT

Go read up on Bernoulli's principle.

I doubt I can say anything that would change your mind but if you assume frictionless wheels the moving belt is completely irrelevant. The relative motion between the plane and the air is the same whether it's sitting on solid ground or a moving belt, and last time I checked a plane has no problem taking off on solid ground. I suggest you look up newton's basic principles of motions, ironically it's his second law which provides the foundation of Bernoulli's principle.

If you still think I'm wrong I don't really know what to say lol, you'd be arguing with probably the most fundamental law of classical mechanics.


edit: I just realized we might even be imagining different scenarios, I'm assuming we're talking frictionless wheels + a belt of infinite length in which case the plane has room to move with a forward velocity. If you're suggesting the plane can't lift off if it's not moving relative to still ground/air then you'd be correct.

[PowerRanger]

It depends if theres snakes on the plane or not

[Trojans86]

..wut............. Thrust's only purpose is to move a plane FORWARD THROUGH THE AIR TO GENERATE LIFT

Thrust doesn't lift a plane into the air....... the air pressure difference above and below a wing is what lifts a plane into the air.....we call this Lift.

ok I'm done ITT... ya'll hit your heads too hard

I think what you are missing is that the wheels are not pulling the plane forward but rather directing the plane like a rudder (sp?) of a boat and providing to low resistance method of fighting gravity.

[ironicinori]

LMFAO!!!!!!!!!!!

what.

The wheels have a very important purpose. They allow Thrust to move the plane forward and achieve the speed necessary for Lift.

I'm done ITT.

It's funny when people think they've owned you. But are literally, physically just wrong. Like if you were arguing against me saying 2+2=4 wrong.

You saying the plane wouldn't move forward if it was hanging on a string from the ceiling?The fukking jets move if forward. Not the wheels. There's only one correct answer and my jimjams are getting rustled at people that think they are right.

Here's the answer at a kindergarten level.
You would need a treadmill as long as a normal runway, and the takeoff would look the same as a plane taking off from the ground normally... except the wheels would spin faster.

[Trojans86]

Say the planes engines make the wheels turn at 15,000 RPM at half thrust (pulled that out of thin air, doesnt matter), and the treadmill also makes the wheels spin at the same RPM. Then the engines are put on full thrust, so the engines cause the wheels to spin at 25,000 RPM, the treadmill then matches this. To a person standing by the side of the treadmill, he sees a stationary plane with wheels spinning incredibly fast.
He can stand on the wing and light a cigarette.
No planes took off that day

The wheels of the plane would adjust an increase to an rpm above that of the treadmill. So if the treadmill is 15,000 then the plane would be 15,001 and increasing.

[Steak_n_Taters]

Say the planes engines make the wheels turn at 15,000 RPM at half thrust (pulled that out of thin air, doesnt matter), and the treadmill also makes the wheels spin at the same RPM. Then the engines are put on full thrust, so the engines cause the wheels to spin at 25,000 RPM, the treadmill then matches this. To a person standing by the side of the treadmill, he sees a stationary plane with wheels spinning incredibly fast.
He can stand on the wing and light a cigarette.
No planes took off that day

The

thrust

and

forward

motion

are

independent

of

wheel

speed

(in this situation)

The speed of the wheels is irrelevant

[Trojans86]

Treadmill
noun

- an exercise machine that allows the user to walk or run in place, usually on a continuous moving belt.

- any monotonous, wearisome routine in which there is little or no satisfactory progress.



I go by the actual definition of a treadmill.

a human generates movement by pushing off the ground, an airplane doesnt.

[Steak_n_Taters]

Treadmill
noun

- an exercise machine that allows the user to walk or run in place, usually on a continuous moving belt.

- any monotonous, wearisome routine in which there is little or no satisfactory progress.



I go by the actual definition of a treadmill.

lol, pretty good subtle trolling.

You know I know what you are doing.

[MrGreenz]

Treadmill
noun

- an exercise machine that allows the user to walk or run in place, usually on a continuous moving belt.

- any monotonous, wearisome routine in which there is little or no satisfactory progress.



I go by the actual definition of a treadmill.

try running in place on a treadmill with a jet engine on your back



treadmills can counteract imparted force of a runner because the running force it is applied to the belt, however when the force isn't imparted to the belt how can it be counteracted?

[nickrut]

The friction in the wheels is negligible relative to the other forces so the plane would move relative to the ground and thus would move. The wheels would be moving twice as fast as they would for the same relative to ground speed though since the treadmill would be moving. Now if the power was generated by the wheels then it'd be a diff story

Engineer here so I'm clearly an expert. Lol

[NoobGains23]

The wheels of the plane would adjust an increase to an rpm above that of the treadmill. So if the treadmill is 15,000 then the plane would be 15,001 and increasing.

Which the treadmill will instantly meet. Result = stationary plane.

[ironicinori]

lol, pretty good subtle trolling.

You know I know what you are doing.

They must be trolling at this point. Well played *******s.

[Trojans86]

here is a way to test it. Put a anything with wheels on a treadmill. Turn the treadmill on and hold the thing with wheels in place so the wheels of the treadmill are obviously matching the treadmill. Then from behind the thihng with wheels, push it forward (which replicates an engine's thrust). It will go forward and the wheels are now moving faster than the treadmill.

[chino3]

why wouldnt a better test be instead of using a treadmill/conveyor belt you use one of these:



or a setup like they use for dyna testing.

it would literally let the wheels spin in any situation as quickly as the bars could roll and vice versa. what would happen then?

[Agentdark45]

I don't even know who's trolling anymore.

[DancerInTheDark]

The question is st00p1d. The treadmill of the problem is not a real treadmill, while the airplane is a real airplane. Intuitively the treadmill *can* exert force on the airplane because of rolling resistance.

So what really happens if you have ubertreadmill of peace which can go up to infinite speed is that speed of treadmill rises to U WOT M8 values, the wheels explode, metal parts start touching ground everywhere, plane nosedives into the ground. If you actually had a very large extremely fast treadmill and you had the plane slowly increase thrust so that treadmill can match it this is what you would observe.

[JaffaJune]

misc is absolute ****nuts. does the plane lift immediately at full thrust? No. why the fok would it lift then when it's at full thrust in the same position.

[Fist-Of-Freedom]

Is it windy when you run on a treadmill?

Tards

[Steak_n_Taters]

misc is absolute ****nuts. does the plane lift immediately at full thrust? No. why the fok would it lift then when it's at full thrust in the same position.

Read my posts and you will know why.

You are wrong, and that's okay, as long as you learn the truth.

[Trojans86]

Human treadmills do.

This is a hypothetical gargantuan AIRPLANE TREADMILL

I assume it lives up to the definition of a Functional treadmill.


If you want to use a treadmill that cannot keep the plane in place, and thus is a crappy treadmill that doesn't live up to the definition of the word........ then yeah, the plane can take off.

Now I know you're trollign but for the last time, a human pushes off the ground (not a human treadmill but a human), which if the ground is a revolving treadmill then it can keep a human in place, whereas a plane pushes off the air so the ground has no impact on what speed the plane is going. Now if we were in a wind turbine the plane could fly without moving forward but that is because it is pushing off of air, not the ground.

[ironicinori]

why wouldnt a better test be instead of using a treadmill/conveyor belt you use one of these:



or a setup like they use for dyna testing.

it would literally let the wheels spin in any situation as quickly as the bars could roll and vice versa. what would happen then?

This explains it perfectly. If you strapped a fukking jet airplane to a dyno, the wheels wouldn't move. Then, the plane would rip free from the dyno, and move forward until it takes off

Can't possibly roll in place on a treadmill, it will still move forward relative to the earth.

[NoobGains23]

here is a way to test it. Put a anything with wheels on a treadmill. Turn the treadmill on and hold the thing with wheels in place so the wheels of the treadmill are obviously matching the treadmill. Then from behind the thihng with wheels, push it forward (which replicates an engine's thrust). It will go forward and the wheels are now moving faster than the treadmill.

This is true.
However if the treadmill can always match the speed of the wheels, it will not move forward. So the plane won't take off. Why is this so hard to understand?

[AdamOm]

No.

If anything, it would create down force because the air would move faster underneath the wings than above.

[MrGreenz]

Human exercise treadmills are meant to keep human bodies in place.

I bet we can design a treadmill that can keep a Human with a Jet Engine in place too.


When OP talks about a giant airplane treadmill, I assume it is designed to keep the plane in place too. Definition of what a treadmill does.


This is all silly arguing over how the treadmill actually works in this scenario. Has to be defined.

Well ok I agree with you, if a treadmill is created that breaks the laws of physics then ya, it stays where it is.

[Steak_n_Taters]

This is true.
However if the treadmill can always match the speed of the wheels, it will not move forward. So the plane won't take off. Why is this so hard to understand?

For this scenario to be tested to its limits, we have to assume frictionless treadmill and wheels. Since there is no friction, the treadmill imparts no directional force on the plane. So, the whole treadmill is moot, regardless of treadmill / wheel speed.

[NoobGains23]

I'll put it as simply as i can to the obvious ****tards ITT.

You have a man on a skateboard which has a jet engine on the back.
You have a treadmill which has a motor which will match any forward speed the skateboard can produce. E.g. Skateboard is rolling at 50mph, treadmill moves at 50mph so skateboard remains stationary on the treadmill belt.

Skateboard brah cranks the engine up to full thrust, which happens to be 300mph. Treadmill meets opposite 300mph speed. Skateboard stays in place. You can put 2 huge ass wings on it if you want, but you could still light a cigarette under the wing. There is no airflow at all.
Idiots

[ironicinori]

This is true.
However if the treadmill can always match the speed of the wheels, it will not move forward. So the plane won't take off. Why is this so hard to understand?

Well, what if you put your hand behind the toy car and put 0 force on it, besides the very little it takes to keep it in place due to friction.

The treadmill could be going 1mph or 1000 mph and it takes the exact same minimal force to keep it in place. This is why if you put actual force behind it (a jet engine) it will just move forward. Actually, while the treadmill is rocketing from 1-1000, you can still just move the toy car back and forth with your hands, as easily as if it was on the ground.


people keep assuming the treadmill can go fast enough to keep the plane in place, when that's not physically possible. It will always move forward just like it wasn't on the treadmill at all.

[MrGreenz]

This is true.
However if the treadmill can always match the speed of the wheels, it will not move forward. So the plane won't take off. Why is this so hard to understand?

The pilot applies the breaks, the pilot goes full throttle, the thrust overcomes the friction of the wheels on the treadmill, the wheels skid along the treadmill without rotating, the plane reaches 180mph and flies off into the distance, luckily there was a fresh set of tyres on the plane