FabSwingers.com > Forums > The Lounge > A physics question

A physics question

By *ralbisw OP Man over a year ago

Exeter

Following from the long maths probability question, how about this:

“A plane is standing on a runway that can move (some sort of band conveyer belt). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in the opposite direction). Can the plane take off?”

Answers on a postcard etc.

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By *iamondjoeMan over a year ago

Glastonbury

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By (user no longer on site) over a year ago

No, because the wings need air flowing over the wings to create lift.

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By *erbyDalesCplCouple over a year ago

Derbyshire

Yes.

(if it's a Harrier)

Mr ddc

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By (user no longer on site) over a year ago

Yes it can and will take off

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By (user no longer on site) over a year ago

"Yes.

(if it's a Harrier)

Mr ddc "

Or a vc10

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By (user no longer on site) over a year ago

"Yes.

(if it's a Harrier)

Mr ddc "

If you can find one in an airworthy condition

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By *ee VianteWoman over a year ago

Somewhere in North Norfolk

"Yes.

(if it's a Harrier)

Mr ddc "

I wouldn't like to see the state of the conveyor belt afterwards though.

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By *rightonsteveMan over a year ago

Brighton - even Hove!

Yes it can. It's the speed of the air that creates a partial vacuum and so lift, not the speed of the plane itself.

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By (user no longer on site) over a year ago

No its a trick question!

The op said the conveyor belt was 'band' therefore they wouldn't be allowed to use it so the experiment would never take place!

Next question please

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By (user no longer on site) over a year ago

Yes, because the aeroplane's motive force is through its engines, not its wheels, so it will accelerate forwards as normal.

The limiting factor will be if its tyres can withstand the added rotational speed caused by the moving runway...

Simple really.....

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By (user no longer on site) over a year ago

No the speed of the wheels is irrelevant, you need the forward motion to create a difference in air pressure to generate lift.

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By (user no longer on site) over a year ago

"Yes, because the aeroplane's motive force is through its engines, not its wheels, so it will accelerate forwards as normal.

The limiting factor will be if its tyres can withstand the added rotational speed caused by the moving runway...

Simple really.....

What she said.

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By (user no longer on site) over a year ago

"No"

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By *lkDomWhtSubBiCpleCouple over a year ago

Somewhere / Everywhere /Kinksville

No the plane takes off through momentum and engine thrust

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By *rightonsteveMan over a year ago

Brighton - even Hove!

"No the plane takes off through momentum and engine thrust "

"Thrust" *snigger*

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By (user no longer on site) over a year ago

"Yes it can. It's the speed of the air that creates a partial vacuum and so lift, not the speed of the plane itself. "

But there wouldn't be an airspeed if the plane itself is essential motionless?

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By (user no longer on site) over a year ago

In all seriousness the plane is essentially motionless due to the opposite direction of the belt cancelling out any forward motion.

The forward motion is essential to the conventional winged aircraft as it produces the airflow over the wing, creating the lift required to enable the aircraft to get off the ground.

Doesn't matter how hard the engines are going or how fast the wheels are turning

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By (user no longer on site) over a year ago

"Yes it can. It's the speed of the air that creates a partial vacuum and so lift, not the speed of the plane itself.

But there wouldn't be an airspeed if the plane itself is essential motionless?"

The plane isn't motionless though

Yes it'll take off.

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By *lkDomWhtSubBiCpleCouple over a year ago

Somewhere / Everywhere /Kinksville

"No the plane takes off through momentum and engine thrust

"Thrust" *snigger*"

So childish. What kind of site do you think this is

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By *rightonsteveMan over a year ago

Brighton - even Hove!

"No the plane takes off through momentum and engine thrust

"Thrust" *snigger*

So childish. What kind of site do you think this is

*abashed*

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By (user no longer on site) over a year ago

The aeroplane wouldn't be motionless - the engines will still drive it forward into the air, regardless of what the runway is doing underneath it.

The moving runway will, however have two effects:

1. if the runway moved in the opposite direction to the 'plane, then it will drag more air undeneath the wings, which will actually increase lift, and so make it take off sooner (leaving out the question fo ground effect drag)

2. the combined forward motion of the 'plane and the opposite motion of the runway will cause the wheels to spin twice as fast - and so the tyres may fail and burst before take-off.

Damn, I thought I'd left physics behind at school - there must still be some ratling around in my head somewhere...

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By (user no longer on site) over a year ago

Fuck it, my head hurts. Who wants a shag instead

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By (user no longer on site) over a year ago

"Fuck it, my head hurts. Who wants a shag instead

If you're having a shag, and you're thrusting your penis forward at a given speed, is it better if the vagina is stationary, or moving in the opposite direction though....?

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By *icolerobbieCouple over a year ago

walsall

I thought he said answers on a post card.....can't you all read

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By (user no longer on site) over a year ago

And if said plane was full of birds and in mid-flight they flapped their wings and lifted off their perches, would the plane get lighter?

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By (user no longer on site) over a year ago

This reminded me of the time I had to correct my maths teacher because she assumed there are 100 minutes in an hour when trying to calculate how long it will take a plane to reach its destination

. I was 13 at the time...

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By *ildt123Man over a year ago

Huddersfield

Yes it will take off, it's a jet there is no force going through the wheels it's air caused by being blown out and lift from the wings. Wheels don't matter not all planes have wheels

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By (user no longer on site) over a year ago

Maybe the rolling runway could create enough difference in air pressure if moving fast enough below the wing that it could create the same force of the Bernoulli Principle, except it may keep the plane grounded?

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By *lkDomWhtSubBiCpleCouple over a year ago

Somewhere / Everywhere /Kinksville

Can we just have the answer now OP please

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By *orwegian BlueMan over a year ago

Iceland, but Aldi is closer..

No, the plane for all intents is stationary.

It has no more chance of lift than you would have of getting to the moon wearing roller skates whilst on a treadmill..

Even with the forward motion from the thrust of the engine, this is countered by the equal and negative motion of the band.

It is the physical forward motion and the air passing across the wings surface that causes the plane to take lift off the ground.

The wing is designed to direct the air flow with more passing under than over the wings surface causing a negative pressure above..

Lift could be achieved by passing enough air across the wings surface using a huge fan, like in a wind tunnel.

However as that air would be turbulent stability could never be achieved in the open space.

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By *lkDomWhtSubBiCpleCouple over a year ago

Somewhere / Everywhere /Kinksville

"No, the plane for all intents is stationary.

It has no more chance of lift than you would have of getting to the moon wearing roller skates whilst on a treadmill..

Even with the forward motion from the thrust of the engine, this is countered by the equal and negative motion of the band.

It is the physical forward motion and the air passing across the wings surface that causes the plane to take lift off the ground.

The wing is designed to direct the air flow with more passing under than over the wings surface causing a negative pressure above..

Lift could be achieved by passing enough air across the wings surface using a huge fan, like in a wind tunnel.

However as that air would be turbulent stability could never be achieved in the open space. "

That's what I said. I just said it in fewer words

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By (user no longer on site) over a year ago

It can't take off because the only motion is the wheels moving against the belt, the belt is matched to the wheels and not the thrusters or engine, the plane is essentially motionless and therefore has zero air speed to lift off

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By (user no longer on site) over a year ago

"The aeroplane wouldn't be motionless - the engines will still drive it forward into the air, regardless of what the runway is doing underneath it.

The moving runway will, however have two effects:

2. the combined forward motion of the 'plane and the opposite motion of the runway will cause the wheels to spin twice as fast - and so the tyres may fail and burst before take-off.

Damn, I thought I'd left physics behind at school - there must still be some ratling around in my head somewhere...

Exactly what is said here.

Since a jet plane is moved by THRUST it is irrelevant what the wheels are doing and what're those wheels are running on. The plane will still be THRUST forward in real terms to create lift and therefore take off.

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By *eliz NelsonMan over a year ago

The Tantric Tea Shop

No!

Definitely not!

Based on Nelsons 'Theory of Watersports'

which states 'It just seems wrong to me!'

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By *annedandtallMan over a year ago

Buckinghamshire

No, because any thrust and therefore forward motion would be equal to the conveyor moving in the opposite direction, thereby keeping the plane stationary. Airspeed, not groundspeed is required for lift and as the plane would be motionless all the thrust in the world isn't going to let it achieve lift.

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By *ralbisw OP Man over a year ago

Exeter

A lot of answers!!!

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By (user no longer on site) over a year ago

I think I'd just go by boat.

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By (user no longer on site) over a year ago

"Yes.

(if it's a Harrier)

Mr ddc

Or a vc10"

What?

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By *eaded_BazMan over a year ago

Truro

"Yes it can and will take off

This it's been proven on one of those myth buster type programmes

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By *unandbuckCouple over a year ago

Sheffield

Its a trick question.

The band is irelevant, because the engine moves forward because of thrust , not its wheels.

Even if the band moves backwards the plane will still move forward as if it was on tarmac.

It will take off as normal.

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By (user no longer on site) over a year ago

"No the plane takes off through momentum and engine thrust

"Thrust" *snigger*"

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By (user no longer on site) over a year ago

Would it make a difference if it was a jet or propellor plane?

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By *lkDomWhtSubBiCpleCouple over a year ago

Somewhere / Everywhere /Kinksville

But no airflow over the wings so it's going no where. We're grounded

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By (user no longer on site) over a year ago

"No, because any thrust and therefore forward motion would be equal to the conveyor moving in the opposite direction, thereby keeping the plane stationary. Airspeed, not groundspeed is required for lift and as the plane would be motionless all the thrust in the world isn't going to let it achieve lift."

Think about it! Jet engine produces THRUST. This is acted upon the air, not the ground. It doesn't matter what the ground is doing, the aircraft will still go forwards in the air.

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By *ackDMissMorganCouple over a year ago

Halifax

"This reminded me of the time I had to correct my maths teacher because she assumed there are 100 minutes in an hour when trying to calculate how long it will take a plane to reach its destination

. I was 13 at the time..."

Your maths teacher thought there were 100 minutes in an hour?

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By *rightonsteveMan over a year ago

Brighton - even Hove!

"This reminded me of the time I had to correct my maths teacher because she assumed there are 100 minutes in an hour when trying to calculate how long it will take a plane to reach its destination

. I was 13 at the time...

Your maths teacher thought there were 100 minutes in an hour?

She was always late for work.

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By *lkDomWhtSubBiCpleCouple over a year ago

Somewhere / Everywhere /Kinksville

"Would it make a difference if it was a jet or propellor plane? "

I'd say less requirement on lift from wings as planes are smaller.

Fact is runways are built for a reason I think

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By (user no longer on site) over a year ago

"Would it make a difference if it was a jet or propellor plane? "

No. it would still take off. The ground has no bearing on the forward motion of an aircraft that is being driven within the air.

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By *unandbuckCouple over a year ago

Sheffield

"Would it make a difference if it was a jet or propellor plane? "

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By *lkDomWhtSubBiCpleCouple over a year ago

Somewhere / Everywhere /Kinksville

Think about it! Jet engine produces THRUST. This is acted upon the air, not the ground. It doesn't matter what the ground is doing, the aircraft will still go forwards in the air. "

But it needs momentum to get lift to start with

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By *avrick15Man over a year ago

glasgow

The answers no, I'm a physicist

If you want to know why go to uni like I did

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By *rightonsteveMan over a year ago

Brighton - even Hove!

The answers no, I'm a physicist

If you want to know why go to uni like I did

I'm an aeroplane driver and I say the answer is yes.

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By *avrick15Man over a year ago

glasgow

The answers no, I'm a physicist

If you want to know why go to uni like I did

I'm an aeroplane driver and I say the answer is yes. "

Surely that's a pilot, being one you'd know that

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By (user no longer on site) over a year ago

Why did the chewing gum cross the road,,,?

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By (user no longer on site) over a year ago

"Why did the chewing gum cross the road,,,?

To fuck the chicken?

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By *lkDomWhtSubBiCpleCouple over a year ago

Somewhere / Everywhere /Kinksville

I'm an aerospace engineer. I think I know a thing or two

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By (user no longer on site) over a year ago

"Why did the chewing gum cross the road,,,?

Something about being stuck to a shoe?

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By (user no longer on site) over a year ago

No if no lift from airpressure over the wing

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By (user no longer on site) over a year ago

Would it matter what colour the plane was?

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By *unandbuckCouple over a year ago

Sheffield

The answers no, I'm a physicist

If you want to know why go to uni like I did

Back to uni for you! It will fly.

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By (user no longer on site) over a year ago

"Would it matter what colour the plane was? "

Yup! Everyone knows that red ones go faster!

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By (user no longer on site) over a year ago

I'm a chef I'm meant to know these things

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By *rightonsteveMan over a year ago

Brighton - even Hove!

The answers no, I'm a physicist

If you want to know why go to uni like I did

I'm an aeroplane driver and I say the answer is yes.

Surely that's a pilot, being one you'd know that

Damn!

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By *rightonsteveMan over a year ago

Brighton - even Hove!

"Would it matter what colour the plane was?

Yup! Everyone knows that red ones go faster!

White is a lighter colour than black so that's why planes are often white cos they is lighter than black ones.

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By (user no longer on site) over a year ago

"Why did the chewing gum cross the road,,,?

Something about being stuck to a shoe?"

Ok half a point...

Full point if you'd said it was stuck on the chickens foot ,,,,

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By *inky-MinxWoman over a year ago

Grantham

I'm in the No camp

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By (user no longer on site) over a year ago

"Why did the chewing gum cross the road,,,?

Something about being stuck to a shoe?

Ok half a point...

Full point if you'd said it was stuck on the chickens foot ,,,,

I got half a point! Whoop! *dances

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By *avrick15Man over a year ago

glasgow

Jesus this is like a job interview aptitude test

Personally I think the chewing gum question is far more of a pressing issue

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By (user no longer on site) over a year ago

"Why did the chewing gum cross the road,,,?

Something about being stuck to a shoe?

Ok half a point...

Full point if you'd said it was stuck on the chickens foot ,,,,

I got half a point! Whoop! *dances "

Enjoy the moment ...

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By (user no longer on site) over a year ago

"Why did the chewing gum cross the road,,,?

Something about being stuck to a shoe?

Ok half a point...

Full point if you'd said it was stuck on the chickens foot ,,,,

I got half a point! Whoop! *dances

Enjoy the moment ...

Thanks

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By *avrick15Man over a year ago

glasgow

I will give you a clue...

if you understand anything about velocity you'll know why it won't lift

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By *orwegian BlueMan over a year ago

Iceland, but Aldi is closer..

"Would it make a difference if it was a jet or propellor plane?

No"

The plane is stationary, it's not gonna take off..

It's nothing to do with thrust, well not in this instance anyway...

Consider a glider, it has no thrust and requires forward motion of being towed to obtain lift..

If it was possible to obtain flight from a conveyer belt, military aircraft carriers would be far smaller and the mod would not need to be investing a few quid on f35 aircraft and a new aircraft carrier plus all the re-qualification work to arm the new aircraft.

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By *avrick15Man over a year ago

glasgow

"Would it make a difference if it was a jet or propellor plane?

The plane is stationary, it's not gonna take off..

It's nothing to do with thrust, well not in this instance anyway...

Consider a glider, it has no thrust and requires forward motion of being towed to obtain lift..

Give that man a new towel

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By (user no longer on site) over a year ago

The answers no, I'm a physicist

If you want to know why go to uni like I did

I think you need to go back to uni then. You obviously sat at the back of the class.

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By (user no longer on site) over a year ago

"Following from the long maths probability question, how about this:

Answers on a postcard etc.

What sort of a plane is it?...because THAT kind of matters..

Some planes don't need speed to take off....

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By *avrick15Man over a year ago

glasgow

The answers no, I'm a physicist

If you want to know why go to uni like I did

I think you need to go back to uni then. You obviously sat at the back of the class. "

Since I can't be arsed typing or arguing here...

So read that and then tell me how a stationary object generates velocity?

The amount of lift generated by an object depends on a number of factors, including the density of the air, the velocity between the object and the air, the viscosity and compressibility of the air, the surface area over which the air flows, the shape of the body, and the body's inclination to the flow, also called the angle of attack.

In general, the dependence on body shape, inclination, air viscosity, and compressibility is very complex. One way to deal with complex dependencies is to characterize the dependence by a single variable. For lift, this variable is called the lift coefficient, designated "Cl". For given air conditions, shape, and inclination of the object, we have to determine a value for Cl to determine the lift. For some simple flow conditions and geometries, and low inclinations, aerodynamicists can now determine the value of Cl mathematically. But, in general, this parameter is determined experimentally using models in a wind tunnel. For thin airfoils, at small angles of attack, the lift coefficient is approximately two times pi (3.14159) times the angle of attack expressed in radians.

Cl = 2 * pi * angle (in radians)

The modern lift equation states that lift is equal to the lift coefficient (Cl) times the density of the air (r) times half of the square of the velocity (V) times the wing area (A).

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By (user no longer on site) over a year ago

No, Bernoulli's principle requires airflow over the wing and as the wing itself is not moving forward there will be no lift.

The air doesn't care what the engines or wheels are doing.

If it isn't forced to travel further over the top of the wing than air passing beneath the wing there will be no lift

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By *unandbuckCouple over a year ago

Sheffield

The plane wont be stationary. The conveyor belt has no way of holding it stationary.

Its not a car driving by its wheels. Its a plane thrusting against air.

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By *avrick15Man over a year ago

glasgow

"No, Bernoulli's principle requires airflow over the wing and as the wing itself is not moving forward there will be no lift.

The air doesn't care what the engines or wheels are doing.

If it isn't forced to travel further over the top of the wing than air passing beneath the wing there will be no lift "

Some aren't listening... getting all caught up in the conveyor belt.. must be a rubber thing

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By *avrick15Man over a year ago

glasgow

"The plane wont be stationary. The conveyor belt has no way of holding it stationary.

Its not a car driving by its wheels. Its a plane thrusting against air."

Arghhhhhhh read the question !!

Plane moving that way belt same speed ie stationary = no airflow or velocity

Fuck me....

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By *inky-MinxWoman over a year ago

Grantham

"The amount of lift generated by an object depends on a number of factors, including the density of the air, the velocity between the object and the air, the viscosity and compressibility of the air, the surface area over which the air flows, the shape of the body, and the body's inclination to the flow, also called the angle of attack.

Cl = 2 * pi * angle (in radians)

The modern lift equation states that lift is equal to the lift coefficient (Cl) times the density of the air (r) times half of the square of the velocity (V) times the wing area (A)."

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By *avrick15Man over a year ago

glasgow

"The plane wont be stationary. The conveyor belt has no way of holding it stationary.

Its not a car driving by its wheels. Its a plane thrusting against air.

Arghhhhhhh read the question !!

Plane moving that way belt same speed ie stationary = no airflow or velocity

Fuck me....

There was opposite arrows in that when I typed it

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By (user no longer on site) over a year ago

Yes

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By (user no longer on site) over a year ago

Plane moving that way belt same speed ie stationary = no airflow or velocity

I'm not getting in this argument with you and the other poster.

But you need to think about what you've just typed...

Read it and re-read it again.

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By *unandbuckCouple over a year ago

Sheffield

"The plane wont be stationary. The conveyor belt has no way of holding it stationary.

Its not a car driving by its wheels. Its a plane thrusting against air.

Arghhhhhhh read the question !!

Plane moving that way belt same speed ie stationary = no airflow or velocity

Fuck me....

How does the conveyor belt moving backwards stop the plane moving forward?

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By *avrick15Man over a year ago

glasgow

Plane moving that way belt same speed ie stationary = no airflow or velocity

I'm not getting in this argument with you and the other poster.

But you need to think about what you've just typed...

Read it and re-read it again."

There was opposite arrows.. mainly because I read the question.. might I suggest you do the same

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By *oncupiscentTonyMan over a year ago

Kent

Bish bosh

https://youtu.be/YORCk1BN7QY

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By *avrick15Man over a year ago

glasgow

"The plane wont be stationary. The conveyor belt has no way of holding it stationary.

Its not a car driving by its wheels. Its a plane thrusting against air.

Arghhhhhhh read the question !!

Plane moving that way belt same speed ie stationary = no airflow or velocity

Fuck me....

How does the conveyor belt moving backwards stop the plane moving forward?"

You ever ran on a treadmill?? Feel the wind rushin through your hair so you??

Can't believe I'm even getting into this

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By (user no longer on site) over a year ago

How does the conveyor belt moving backwards stop the plane moving forward?"

^ sort of this.

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By (user no longer on site) over a year ago

"Following from the long maths probability question, how about this:

Answers on a postcard etc.

According to a scientist who's appeared on a podcast I listened to it could as the engine would eventually build up enough speed that it would essentially be weightless and a gust of wind could propel it into the air

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By *avrick15Man over a year ago

glasgow

"Following from the long maths probability question, how about this:

Answers on a postcard etc.

Probability over a large radius, massive inefficiency, instability and countering basic lift efficiency according to the laws of physics makes that reasonable but a pointless scientific statement

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By (user no longer on site) over a year ago

"Following from the long maths probability question, how about this:

Answers on a postcard etc.

Depends on if the pilot has a big cock.

Everyone knows big cocks are better.

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By *unandbuckCouple over a year ago

Sheffield

"The plane wont be stationary. The conveyor belt has no way of holding it stationary.

Its not a car driving by its wheels. Its a plane thrusting against air.

Arghhhhhhh read the question !!

Plane moving that way belt same speed ie stationary = no airflow or velocity

Fuck me....

How does the conveyor belt moving backwards stop the plane moving forward?

You ever ran on a treadmill?? Feel the wind rushin through your hair so you??

Can't believe I'm even getting into this"

Thats the difference. I move forward by my feet pushing against the floor. A treadmill can keep me stationary by travelling at yhe exact opposite speed.

A plane moves forward by pushing against the air.

The conveyor doesnt affect the air.

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By *avrick15Man over a year ago

glasgow

"The plane wont be stationary. The conveyor belt has no way of holding it stationary.

Its not a car driving by its wheels. Its a plane thrusting against air.

Arghhhhhhh read the question !!

Plane moving that way belt same speed ie stationary = no airflow or velocity

Fuck me....

How does the conveyor belt moving backwards stop the plane moving forward?

You ever ran on a treadmill?? Feel the wind rushin through your hair so you??

Can't believe I'm even getting into this

Thats the difference. I move forward by my feet pushing against the floor. A treadmill can keep me stationary by travelling at yhe exact opposite speed.

A plane moves forward by pushing against the air.

The conveyor doesnt affect the air.

so the wheels aren't touching the ground as the plane moves forward and the belt in opposite direction, at the exact same speed just like your feet and treadmill?

Tell me the difference ?

Now I'm intrigued in your logic

Reply privately (closed, thread got too big)

By *oncupiscentTonyMan over a year ago

Kent

"The plane wont be stationary. The conveyor belt has no way of holding it stationary.

Its not a car driving by its wheels. Its a plane thrusting against air.

Arghhhhhhh read the question !!

Plane moving that way belt same speed ie stationary = no airflow or velocity

Fuck me....

How does the conveyor belt moving backwards stop the plane moving forward?

You ever ran on a treadmill?? Feel the wind rushin through your hair so you??

Can't believe I'm even getting into this

Thats the difference. I move forward by my feet pushing against the floor. A treadmill can keep me stationary by travelling at yhe exact opposite speed.

A plane moves forward by pushing against the air.

The conveyor doesnt affect the air.

so the wheels aren't touching the ground as the plane moves forward and the belt in opposite direction, at the exact same speed just like your feet and treadmill?

Tell me the difference ?

Now I'm intrigued in your logic "

Jesus Christ because on a treadmill your legs are powered but there's no power to a planes wheels ffs!

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By *orwegian BlueMan over a year ago

Iceland, but Aldi is closer..

A standard fixed wing aircraft cannot take off, however a rotary wing aircraft would be able to obtain lift..

Just throwing that in the mix

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By *aul DeUther-OneMan over a year ago

Sussex

If it were possible to get an aircraft airborne from a conveyor belt travelling in the opposite direction we wouldn't need airfields with runways. Also, a lot of aircraft carriers use catapults to accelerate the aircraft forwards to increase the airspeed -opposite of the band mentioned in the question.

So, no the plane will not fly (unless a freaky gust of wind picks it up like a kite)

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By (user no longer on site) over a year ago

Right then, I'll stand corrected from my original answer after seeing this.

https://m.youtube.com/watch?v=0ul_5DtMLhc

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By *avrick15Man over a year ago

glasgow

"The plane wont be stationary. The conveyor belt has no way of holding it stationary.

Its not a car driving by its wheels. Its a plane thrusting against air.

Arghhhhhhh read the question !!

Plane moving that way belt same speed ie stationary = no airflow or velocity

Fuck me....

How does the conveyor belt moving backwards stop the plane moving forward?

You ever ran on a treadmill?? Feel the wind rushin through your hair so you??

Can't believe I'm even getting into this

Thats the difference. I move forward by my feet pushing against the floor. A treadmill can keep me stationary by travelling at yhe exact opposite speed.

A plane moves forward by pushing against the air.

The conveyor doesnt affect the air.

so the wheels aren't touching the ground as the plane moves forward and the belt in opposite direction, at the exact same speed just like your feet and treadmill?

Tell me the difference ?

Now I'm intrigued in your logic

Jesus Christ because on a treadmill your legs are powered but there's no power to a planes wheels ffs!"

Ha ha my god... so your legs aren't providing thrust just like the engine is... the power transfers down to the wheels moving the chassis forward... remember how the plane taxis to the runway?

So... if on the belt and they both start at the same time/speed, engine thrust and belt speed are you saying this is completely different to the same equation as you running harder and the treadmill increasing speed simultaneously ?

Somehow the plane has lift and airflow and you don't?

Wow...

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By (user no longer on site) over a year ago

Bunandbuck. Dont waste breath. You're banging your head on a brick wall. Some folk really cannot see logic.

I'd also like to know how running on a treadmill has any similarity to a jet engine pushing air through it to generate THRUST. These others obviously believe the engines drive the plane's wheels in the same way your legs run on a treadmill.

Maybe he should run on a treadmill holding a jet engine and let's see if it pushes him off it or in his theory it wouldn't have any effect at all

Reply privately (closed, thread got too big)

By *avrick15Man over a year ago

glasgow

"Bunandbuck. Dont waste breath. You're banging your head on a brick wall. Some folk really cannot see logic.

Maybe he should run on a treadmill holding a jet engine and let's see if it pushes him off it or in his theory it wouldn't have any effect at all

What colour is the sky in your world?

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By (user no longer on site) over a year ago

"Following from the long maths probability question, how about this:

Answers on a postcard etc.

"
.

Depends on the wind speed and direction

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By *lkDomWhtSubBiCpleCouple over a year ago

Somewhere / Everywhere /Kinksville

How does the conveyor belt moving backwards stop the plane moving forward?

^ sort of this.

Because they are in equilibrium momentum. Therefore the plane does not move forward

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By *avrick15Man over a year ago

glasgow

"Bunandbuck. Dont waste breath. You're banging your head on a brick wall. Some folk really cannot see logic.

Maybe he should run on a treadmill holding a jet engine and let's see if it pushes him off it or in his theory it wouldn't have any effect at all

And just for clarity I said the thrust pulls the chassis which the wheels are attached to. There isn't a driveshaft in them. Just to be clear

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By *ohnaronMan over a year ago

london

I am going to build a rubber powered Copland wakefield model aircraft (circa 1948) and put it on Sainsbury's check out conveyor to settle this once and for all.

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By *oncupiscentTonyMan over a year ago

Kent

"The plane wont be stationary. The conveyor belt has no way of holding it stationary.

Its not a car driving by its wheels. Its a plane thrusting against air.

Arghhhhhhh read the question !!

Plane moving that way belt same speed ie stationary = no airflow or velocity

Fuck me....

How does the conveyor belt moving backwards stop the plane moving forward?

You ever ran on a treadmill?? Feel the wind rushin through your hair so you??

Can't believe I'm even getting into this

Thats the difference. I move forward by my feet pushing against the floor. A treadmill can keep me stationary by travelling at yhe exact opposite speed.

A plane moves forward by pushing against the air.

The conveyor doesnt affect the air.

so the wheels aren't touching the ground as the plane moves forward and the belt in opposite direction, at the exact same speed just like your feet and treadmill?

Tell me the difference ?

Now I'm intrigued in your logic

Jesus Christ because on a treadmill your legs are powered but there's no power to a planes wheels ffs!

Ha ha my god... so your legs aren't providing thrust just like the engine is... the power transfers down to the wheels moving the chassis forward... remember how the plane taxis to the runway?

Somehow the plane has lift and airflow and you don't?

Wow...

NOOOOOOOOOOOO!!!!!!, at no point is the engine powering the wheels!!!!!!, it is pushing air over the wing creating lower pressure above the wing than below thus generating lift

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By *avrick15Man over a year ago

glasgow

I'm out.. thank Christ aviation techs aren't easy jobs to come by

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By *lkDomWhtSubBiCpleCouple over a year ago

Somewhere / Everywhere /Kinksville

I think the treadmill example proved useful to explain opposite and opposing forces. If they are equal then they cancel out

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By *avrick15Man over a year ago

glasgow

"I think the treadmill example proved useful to explain opposite and opposing forces. If they are equal then they cancel out "

Thanks but your wasting your breath here because logical comparisons of opposite forces is a shite example against a jet engine!

Which has an exact opposite force... as the question states but hey what the fuck do I know

Lol mental

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By (user no longer on site) over a year ago

This is years old & people are still debating it

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By *alandNitaCouple over a year ago

Scunthorpe

Been reading this with interest...

Sorry Bun & Buck, much as I love you... you (and others) are wrong.

I may not be an engineer but I did do A level Physics.

Thrust is irrelevant, there is no forward motion so the plan will not take off. I won't repeat the explanations already given.

Nita

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By (user no longer on site) over a year ago

I'm amazed at just how much interest this has caused. Great post OP.

I'm also surprised at how indepth some of the wrong answers are

The wheels will just be doing twice the speed of the plane, other than that they have nothing to do with it.

Plane will take off as normal apart from the minimal extra drag caused by the doubling of the rotational wheel speed.

The forward thrust be it from a jet or prop has nothing to do with the ground.

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By *avrick15Man over a year ago

glasgow

"Been reading this with interest...

Sorry Bun & Buck, much as I love you... you (and others) are wrong.

I may not be an engineer but I did do A level Physics.

Thrust is irrelevant, there is no forward motion so the plan will not take off. I won't repeat the explanations already given.

Nita

Hoorah... thank you

And nice tights

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By (user no longer on site) over a year ago

As posted earlier myth busters have proved yes it will take off

Ads

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By (user no longer on site) over a year ago

Thrust is irrelevant, there is no forward motion so the plan will not take off. I won't repeat the explanations already given.

Nita

Where does it say that there isn't any forward motion?

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By (user no longer on site) over a year ago

Thanks but your wasting your breath here because logical comparisons of opposite forces is a shite example against a jet engine!

Which has an exact opposite force... as the question states but hey what the fuck do I know

Lol mental "

'...your wasting' Like I say. Sat at the back of the class

Reply privately (closed, thread got too big)

By *avrick15Man over a year ago

glasgow

Thanks but your wasting your breath here because logical comparisons of opposite forces is a shite example against a jet engine!

Which has an exact opposite force... as the question states but hey what the fuck do I know

Lol mental

'...your wasting' Like I say. Sat at the back of the class

You're as in you are.. I guess you were there too in English class

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By (user no longer on site) over a year ago

"Been reading this with interest...

Sorry Bun & Buck, much as I love you... you (and others) are wrong.

I may not be an engineer but I did do A level Physics.

Thrust is irrelevant, there is no forward motion so the plan will not take off. I won't repeat the explanations already given.

Nita

Hoorah... thank you

And nice tights

There WILL be forward motion irrelevant of the conveyor speed.

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By *lkDomWhtSubBiCpleCouple over a year ago

Somewhere / Everywhere /Kinksville

Can someone wake me please when the OP confirms answer

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By (user no longer on site) over a year ago

The answer is....

Sheep!

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By *avrick15Man over a year ago

glasgow

"Been reading this with interest...

Sorry Bun & Buck, much as I love you... you (and others) are wrong.

I may not be an engineer but I did do A level Physics.

Thrust is irrelevant, there is no forward motion so the plan will not take off. I won't repeat the explanations already given.

Nita

Hoorah... thank you

And nice tights

There WILL be forward motion irrelevant of the conveyor speed. "

Explain one thing... how will there be forward motion if the belt and plane move in opposite directions at the exact same time?

Explain that and I will agree with you

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By *alandNitaCouple over a year ago

Scunthorpe

"Been reading this with interest...

Sorry Bun & Buck, much as I love you... you (and others) are wrong.

I may not be an engineer but I did do A level Physics.

Thrust is irrelevant, there is no forward motion so the plan will not take off. I won't repeat the explanations already given.

Nita

Hoorah... thank you

And nice tights

There WILL be forward motion irrelevant of the conveyor speed. "

How?

The conveyor is cancelling it out according to the question posed.

Thrust (force if you wish) and forward motion are not the same thing.

Oh God., I wish I'd not got involved... going to bed I think

Nita

Reply privately (closed, thread got too big)

By *avrick15Man over a year ago

glasgow

"Been reading this with interest...

Sorry Bun & Buck, much as I love you... you (and others) are wrong.

I may not be an engineer but I did do A level Physics.

Thrust is irrelevant, there is no forward motion so the plan will not take off. I won't repeat the explanations already given.

Nita

Hoorah... thank you

And nice tights

There WILL be forward motion irrelevant of the conveyor speed.

How?

The conveyor is cancelling it out according to the question posed.

Thrust (force if you wish) and forward motion are not the same thing.

Oh God., I wish I'd not got involved... going to bed I think

Nita

Nina can I come?

Reply privately (closed, thread got too big)

By *inky-MinxWoman over a year ago

Grantham

"The plane wont be stationary. The conveyor belt has no way of holding it stationary.

Its not a car driving by its wheels. Its a plane thrusting against air.

Arghhhhhhh read the question !!

Plane moving that way belt same speed ie stationary = no airflow or velocity

Fuck me....

How does the conveyor belt moving backwards stop the plane moving forward?

You ever ran on a treadmill?? Feel the wind rushin through your hair so you??

Can't believe I'm even getting into this

Thats the difference. I move forward by my feet pushing against the floor. A treadmill can keep me stationary by travelling at yhe exact opposite speed.

A plane moves forward by pushing against the air.

The conveyor doesnt affect the air.

so the wheels aren't touching the ground as the plane moves forward and the belt in opposite direction, at the exact same speed just like your feet and treadmill?

Tell me the difference ?

Now I'm intrigued in your logic "

And I'm in

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By *aul DeUther-OneMan over a year ago

Sussex

Aaaargh. Surely this is a trick question as the only aircraft that might be able to get airborne from a conveyor belt would be a helicopter or VSTOL rather than an ordinary 'plane'

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By *avrick15Man over a year ago

glasgow

"The plane wont be stationary. The conveyor belt has no way of holding it stationary.

Its not a car driving by its wheels. Its a plane thrusting against air.

Arghhhhhhh read the question !!

Plane moving that way belt same speed ie stationary = no airflow or velocity

Fuck me....

How does the conveyor belt moving backwards stop the plane moving forward?

You ever ran on a treadmill?? Feel the wind rushin through your hair so you??

Can't believe I'm even getting into this

Thats the difference. I move forward by my feet pushing against the floor. A treadmill can keep me stationary by travelling at yhe exact opposite speed.

A plane moves forward by pushing against the air.

The conveyor doesnt affect the air.

so the wheels aren't touching the ground as the plane moves forward and the belt in opposite direction, at the exact same speed just like your feet and treadmill?

Tell me the difference ?

Now I'm intrigued in your logic

And I'm in

Very kind of you

This is pissing me off tho lol basic fckin physics

Reply privately (closed, thread got too big)

By *alandNitaCouple over a year ago

Scunthorpe

"Been reading this with interest...

Sorry Bun & Buck, much as I love you... you (and others) are wrong.

I may not be an engineer but I did do A level Physics.

Thrust is irrelevant, there is no forward motion so the plan will not take off. I won't repeat the explanations already given.

Nita

Hoorah... thank you

And nice tights

There WILL be forward motion irrelevant of the conveyor speed.

How?

The conveyor is cancelling it out according to the question posed.

Thrust (force if you wish) and forward motion are not the same thing.

Oh God., I wish I'd not got involved... going to bed I think

Nita

Nina can I come?

Think I would be well asleep by the time you got here... and not much space in our bed for three.

I love a Scots accent ...

Nita

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By *inky-MinxWoman over a year ago

Grantham

"The plane wont be stationary. The conveyor belt has no way of holding it stationary.

Its not a car driving by its wheels. Its a plane thrusting against air.

Arghhhhhhh read the question !!

Plane moving that way belt same speed ie stationary = no airflow or velocity

Fuck me....

How does the conveyor belt moving backwards stop the plane moving forward?

You ever ran on a treadmill?? Feel the wind rushin through your hair so you??

Can't believe I'm even getting into this

Thats the difference. I move forward by my feet pushing against the floor. A treadmill can keep me stationary by travelling at yhe exact opposite speed.

A plane moves forward by pushing against the air.

The conveyor doesnt affect the air.

so the wheels aren't touching the ground as the plane moves forward and the belt in opposite direction, at the exact same speed just like your feet and treadmill?

Tell me the difference ?

Now I'm intrigued in your logic

And I'm in

Very kind of you

This is pissing me off tho lol basic fckin physics "

I can tell, but you're doing well

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By *avrick15Man over a year ago

glasgow

"Been reading this with interest...

Sorry Bun & Buck, much as I love you... you (and others) are wrong.

I may not be an engineer but I did do A level Physics.

Thrust is irrelevant, there is no forward motion so the plan will not take off. I won't repeat the explanations already given.

Nita

Hoorah... thank you

And nice tights

There WILL be forward motion irrelevant of the conveyor speed.

How?

The conveyor is cancelling it out according to the question posed.

Thrust (force if you wish) and forward motion are not the same thing.

Oh God., I wish I'd not got involved... going to bed I think

Nita

Nina can I come?

Think I would be well asleep by the time you got here... and not much space in our bed for three.

I love a Scots accent ...

Nita"

Well you never know when I might be in town...

Buy you and the hubby a cocktail or two to celebrate synergy in basic physics

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By (user no longer on site) over a year ago

I still want to know how a VC10 is similar in flight characteristics to a Harrier..

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By *inky-MinxWoman over a year ago

Grantham

How about put someone on a treadmill and get them to run really fast. The treadmill will go as fast as the person runs.

Then get them to put their arms out sideways and see if they can take off

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By *inky-MinxWoman over a year ago

Grantham

" I still want to know how a VC10 is similar in flight characteristics to a Harrier.."

That did cross my mind. VC10's are form the 50s?

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By (user no longer on site) over a year ago

The plane's wings need to be going through the wind at a considerable speed to provide lift. If the plane isn't moving due to the conveyor belt, then the wings won't have the ability to provide the aircraft with enough lift to take off.

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By *eliz NelsonMan over a year ago

The Tantric Tea Shop

"How about put someone on a treadmill and get them to run really fast. The treadmill will go as fast as the person runs.

Then get them to put their arms out sideways and see if they can take off

A 'slapstick cartoon' scenario comes to mind here....but I think I am with you on this one....The Spike Milligan school of physics

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By *avrick15Man over a year ago

glasgow

"The plane's wings need to be going through the wind at a considerable speed to provide lift. If the plane isn't moving due to the conveyor belt, then the wings won't have the ability to provide the aircraft with enough lift to take off.

Bingo... another one.. forward motion=velocity means airflow and lift. #mic drop

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By (user no longer on site) over a year ago

Bingo... another one.. forward motion=velocity means airflow and lift. #mic drop

Skadoosh!

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By (user no longer on site) over a year ago

"How about put someone on a treadmill and get them to run really fast. The treadmill will go as fast as the person runs.

Then get them to put their arms out sideways and see if they can take off

I've tried that without the treadmill. It still doesn't work

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By (user no longer on site) over a year ago

In the absence of wind or the capability of vertical take off, the answer is No.

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By *ureTemptationWoman over a year ago

Off the grid

Fucked if I know. I prefer biology.

Reply privately (closed, thread got too big)

By *oncupiscentTonyMan over a year ago

Kent

"The plane wont be stationary. The conveyor belt has no way of holding it stationary.

Its not a car driving by its wheels. Its a plane thrusting against air.

Arghhhhhhh read the question !!

Plane moving that way belt same speed ie stationary = no airflow or velocity

Fuck me....

How does the conveyor belt moving backwards stop the plane moving forward?

You ever ran on a treadmill?? Feel the wind rushin through your hair so you??

Can't believe I'm even getting into this

Thats the difference. I move forward by my feet pushing against the floor. A treadmill can keep me stationary by travelling at yhe exact opposite speed.

A plane moves forward by pushing against the air.

The conveyor doesnt affect the air.

so the wheels aren't touching the ground as the plane moves forward and the belt in opposite direction, at the exact same speed just like your feet and treadmill?

Tell me the difference ?

Now I'm intrigued in your logic

And I'm in

Very kind of you

This is pissing me off tho lol basic fckin physics "

You're right it is basic physics...thrust from the propeller accelerates the plane through the AIR regardless of the wheels relationship to the GROUND!!

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By *avrick15Man over a year ago

glasgow

"Fucked if I know. I prefer biology.

Now there's a better offer

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By (user no longer on site) over a year ago

Finally found the clip.......

https://youtu.be/YORCk1BN7QY

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By *avrick15Man over a year ago

glasgow

"The plane wont be stationary. The conveyor belt has no way of holding it stationary.

Its not a car driving by its wheels. Its a plane thrusting against air.

Arghhhhhhh read the question !!

Plane moving that way belt same speed ie stationary = no airflow or velocity

Fuck me....

How does the conveyor belt moving backwards stop the plane moving forward?

You ever ran on a treadmill?? Feel the wind rushin through your hair so you??

Can't believe I'm even getting into this

Thats the difference. I move forward by my feet pushing against the floor. A treadmill can keep me stationary by travelling at yhe exact opposite speed.

A plane moves forward by pushing against the air.

The conveyor doesnt affect the air.

so the wheels aren't touching the ground as the plane moves forward and the belt in opposite direction, at the exact same speed just like your feet and treadmill?

Tell me the difference ?

Now I'm intrigued in your logic

And I'm in

Very kind of you

This is pissing me off tho lol basic fckin physics

You're right it is basic physics...thrust from the propeller accelerates the plane through the AIR regardless of the wheels relationship to the GROUND!!"

Now it's a propeller plane and not a jet... and missing completely that the opposite force trying to drag it backwards is being cancelled out by either this fictitious jet or propeller thrust.. still no forward motion

Sigh

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By *ohnaronMan over a year ago

london

I trust we are ignoring ground effects and do we get another sheet of paper to use as we see fit?

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By (user no longer on site) over a year ago

2008!

https://www.youtube.com/watch?v=YORCk1BN7QY

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By *oncupiscentTonyMan over a year ago

Kent

"The plane wont be stationary. The conveyor belt has no way of holding it stationary.

Its not a car driving by its wheels. Its a plane thrusting against air.

Arghhhhhhh read the question !!

Plane moving that way belt same speed ie stationary = no airflow or velocity

Fuck me....

How does the conveyor belt moving backwards stop the plane moving forward?

You ever ran on a treadmill?? Feel the wind rushin through your hair so you??

Can't believe I'm even getting into this

Thats the difference. I move forward by my feet pushing against the floor. A treadmill can keep me stationary by travelling at yhe exact opposite speed.

A plane moves forward by pushing against the air.

The conveyor doesnt affect the air.

so the wheels aren't touching the ground as the plane moves forward and the belt in opposite direction, at the exact same speed just like your feet and treadmill?

Tell me the difference ?

Now I'm intrigued in your logic

And I'm in

Very kind of you

This is pissing me off tho lol basic fckin physics

You're right it is basic physics...thrust from the propeller accelerates the plane through the AIR regardless of the wheels relationship to the GROUND!!

Sigh

Whether it's a prop, jet, push prop or turbo prop it's the relationship of thrust to air not thrust to ground which achieves lift!

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By *nG1967Man over a year ago

perth

loving the made up physics/engineering by the yes voters.

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By (user no longer on site) over a year ago

Our physics teacher had the most amazing eyebrows ever. Plus he looked like penfold.

xxx

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By (user no longer on site) over a year ago

Why do people ignore the answer when it's posted......

https://youtu.be/YORCk1BN7QY

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By *ohnaronMan over a year ago

london

But what if the conveyor belt is at the north pole so it is also rotating?

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By (user no longer on site) over a year ago

"But what if the conveyor belt is at the north pole so it is also rotating?"

Then it would go downwards and corkscrew its way through to Antartica

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By *inky-MinxWoman over a year ago

Grantham

"How about put someone on a treadmill and get them to run really fast. The treadmill will go as fast as the person runs.

Then get them to put their arms out sideways and see if they can take off

A 'slapstick cartoon' scenario comes to mind here....but I think I am with you on this one....The Spike Milligan school of physics

Reply privately (closed, thread got too big)

By *inky-MinxWoman over a year ago

Grantham

"How about put someone on a treadmill and get them to run really fast. The treadmill will go as fast as the person runs.

Then get them to put their arms out sideways and see if they can take off

I've tried that without the treadmill. It still doesn't work

You'll have to show me

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By *inky-MinxWoman over a year ago

Grantham

"Why do people ignore the answer when it's posted......

https://youtu.be/YORCk1BN7QY

Because it's more intersting to use our brains?

Reply privately (closed, thread got too big)

By (user no longer on site) over a year ago

"How about put someone on a treadmill and get them to run really fast. The treadmill will go as fast as the person runs.

Then get them to put their arms out sideways and see if they can take off

I've tried that without the treadmill. It still doesn't work

You'll have to show me

It's not an attractive look. Naked does equal streamlined though!

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By *unandbuckCouple over a year ago

Sheffield

Ok i did a level physics too.

Walking on a treadmill is one thing everybody understands that and thats why it feels a weird question.

When we walk we go forward because of the force exerted on the ground my our feet. So a reverse moving treadmill keeps us staitonary.

The planes wheels free spin on its axle and cannot exert any reverse force on the plane. Therefore the jet thrust only has to accelerate the mass of the plane.

The plane moves forward as it would on a runway.

The moving treadmill is an irrelevant factor (apart from any small fraction in the axle).

Nobody is suggesting a stationary plane would take off, just that the plane moves forward as normal and consequently eventually takes off.

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By *enard ArgenteMan over a year ago

London and France

Of course it takes off; the speed of the conveyor belt has no influence on the speed of the aircraft.

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By (user no longer on site) over a year ago

[Removed by poster at 17/11/16 22:25:55]

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By *ust RachelTV/TS over a year ago

Horsham

Myth busters proved this won't work.

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By (user no longer on site) over a year ago

"Why do people ignore the answer when it's posted......

https://youtu.be/YORCk1BN7QY

Because it's more intersting to use our brains?"

That's probably the best answer yet

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By (user no longer on site) over a year ago

"Myth busters proved this won't work. "

They proved that it does work.

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By (user no longer on site) over a year ago

"How about put someone on a treadmill and get them to run really fast. The treadmill will go as fast as the person runs.

Then get them to put their arms out sideways and see if they can take off

I've tried that without the treadmill. It still doesn't work

You'll have to show me

Tried this, this morning nearly fell off the bloody thing.

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By (user no longer on site) over a year ago

"Ok i did a level physics too.

Walking on a treadmill is one thing everybody understands that and thats why it feels a weird question.

When we walk we go forward because of the force exerted on the ground my our feet. So a reverse moving treadmill keeps us staitonary.

The planes wheels free spin on its axle and cannot exert any reverse force on the plane. Therefore the jet thrust only has to accelerate the mass of the plane.

The plane moves forward as it would on a runway.

The moving treadmill is an irrelevant factor (apart from any small fraction in the axle).

Nobody is suggesting a stationary plane would take off, just that the plane moves forward as normal and consequently eventually takes off."

So why don't we just do away with aeroplane wheels, since the damn things are so obviously redundant!

Let the fuckers levitate!

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By (user no longer on site) over a year ago

"Of course it takes off; the speed of the conveyor belt has no influence on the speed of the aircraft."

Actually, that's a good point! The thrust comes from the turbines, not the wheels. If the wheels on the aircraft can handle the speed of the aircraft's acceleration and the opposing speed of the conveyor belt, then it should take off! Damn, how did I miss that

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By (user no longer on site) over a year ago

"Following from the long maths probability question, how about this:

Answers on a postcard etc.

Yes, they did this experiment on mythbusters. Basically because the engine isn't driving the wheels it makes no difference if the ground is moving in an equal and opposite direction

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By *ee VianteWoman over a year ago

Somewhere in North Norfolk

"Ok i did a level physics too.

Walking on a treadmill is one thing everybody understands that and thats why it feels a weird question.

When we walk we go forward because of the force exerted on the ground my our feet. So a reverse moving treadmill keeps us staitonary.

The planes wheels free spin on its axle and cannot exert any reverse force on the plane. Therefore the jet thrust only has to accelerate the mass of the plane.

The plane moves forward as it would on a runway.

The moving treadmill is an irrelevant factor (apart from any small fraction in the axle).

Nobody is suggesting a stationary plane would take off, just that the plane moves forward as normal and consequently eventually takes off.

So why don't we just do away with aeroplane wheels, since the damn things are so obviously redundant!

Let the fuckers levitate!

They are redundant in terms of moving the plane forward. They only stop the rest of the plane from dragging on the ground.

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By (user no longer on site) over a year ago

"Yes.

(if it's a Harrier)

Mr ddc

If you can find one in an airworthy condition

Yanks are still flying them, in fact they bought all ours in the cheap for spares

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By *ee VianteWoman over a year ago

Somewhere in North Norfolk

"Ok i did a level physics too.

Walking on a treadmill is one thing everybody understands that and thats why it feels a weird question.

When we walk we go forward because of the force exerted on the ground my our feet. So a reverse moving treadmill keeps us staitonary.

The planes wheels free spin on its axle and cannot exert any reverse force on the plane. Therefore the jet thrust only has to accelerate the mass of the plane.

The plane moves forward as it would on a runway.

The moving treadmill is an irrelevant factor (apart from any small fraction in the axle).

Nobody is suggesting a stationary plane would take off, just that the plane moves forward as normal and consequently eventually takes off."

Yes!

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By (user no longer on site) over a year ago

"So why don't we just do away with aeroplane wheels, since the damn things are so obviously redundant!

Let the fuckers levitate!

Some already do - taking off on water/ice etc.

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By *unandbuckCouple over a year ago

Sheffield

"Ok i did a level physics too.

Walking on a treadmill is one thing everybody understands that and thats why it feels a weird question.

When we walk we go forward because of the force exerted on the ground my our feet. So a reverse moving treadmill keeps us staitonary.

The planes wheels free spin on its axle and cannot exert any reverse force on the plane. Therefore the jet thrust only has to accelerate the mass of the plane.

The plane moves forward as it would on a runway.

The moving treadmill is an irrelevant factor (apart from any small fraction in the axle).

Nobody is suggesting a stationary plane would take off, just that the plane moves forward as normal and consequently eventually takes off.

So why don't we just do away with aeroplane wheels, since the damn things are so obviously redundant!

Let the fuckers levitate!

They are redundant in terms of moving the plane forward. They only stop the rest of the plane from dragging on the ground."

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By (user no longer on site) over a year ago

THE PLANE WILL TAKE OFF. IT DOESNT MATTER IF ITS JET OR TURBOPROP. IT WILL TAKE OFF.

THE PLANE WILL

BE MOVINVG FORWARD. IT WILL NOT BE STATIONARY. IT WILL HAVE LIFT.

IT WILL TAKE OFF. !!

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By (user no longer on site) over a year ago

GOODNIGHT xxx

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By (user no longer on site) over a year ago

What about if the earth changes direction and spins faster?

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By (user no longer on site) over a year ago

For the plane to move on the ground it must overcome the "drag" caused by the ground on the wheels. The movement of the conveyor belt as described in the original post will mean that the drag increases at the same rate but in the opposite direction to the force trying to move the wheels.Therefore the forces cancel each other out. The engine thrust will directly move the plane once it's taken off as all the drag is then caused by air through which the plane is flying. To confuse things further when Concorde was flying supersonic approximately 80% of the thrust was applied at the engine intakes and only the other 20% was by thrust out of the rear of the engine.This illustrates the fact it's where the energy is applied that is important and not where it's changed from potential energy into kinetic energy.

If this conveyor belt was put on an aircraft carrier all the people on the deck would disappear over the afternoon end of the carrier.

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By (user no longer on site) over a year ago

"So why don't we just do away with aeroplane wheels, since the damn things are so obviously redundant!

Let the fuckers levitate!

Some already do - taking off on water/ice etc."

Enlighten me as to which planes can levitate?! (as in "float")

Aside from vtol planes which obviously only "levitate" with assistance from the engines

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By (user no longer on site) over a year ago

too funny

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By (user no longer on site) over a year ago

The answers no, I'm a physicist

If you want to know why go to uni like I did

I'm an aeroplane driver and I say the answer is yes.

Surely that's a pilot, being one you'd know that

Well I am a d*unk, so I spend a lot of time talking to bloke down the pub... The answer is yes as the conveyor belt would not have any practical effect except to spin the wheels faster as stated above...

Now if you could create a vacuum of equal volume to the thrust of each engine.. that would be silly

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By *unandbuckCouple over a year ago

Sheffield

Ive just had my mate prof Brian Cox on the phone, he confirmed the plane flies as normal.

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By *aucy tiggerWoman over a year ago

Back where I belong

I do love this thread, thank you OP - personally I don't give a flying fuck if the plane takes off or not! But this has to win a prize for causing people to get themselves all worked up.

PS as Mrs SB would say, "fancy a fuck"?

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