This Should Leave Your Brain In A Knot- Part 2!

[ohiosrt10]

I spent the afternoon with two friends and posed this question to them.
Both are professional pilots: one pilots an Airbus A320 for United; the other just moved from a CRJ with USAir to a brand new Global 5000 and is a private pilot for The Limited (Victoria's Secret).
Both have over 12,000 hrs. of flight time, each (that's almost 1.5 continuous YEARS behind the controls. Each.).

One answered, "Yes. It will take off."
The other, "No. Ground speed is zero. It will not take off."

I don't feel safe now....

 

[nycstev]

You need airflow over the wings to create a low pressure area on on side and a high pressure on the other side . This is what gives it lifting force. So if the plane has niether forward motion or lifting force how can it take off?

 

[ntw0rk]

You need airflow over the wings to create a low pressure area on on side and a high pressure on the other side . This is what gives it lifting force. So if the plane has niether forward motion or lifting force how can it take off?

This is true, but forward motion can be achieved in this scenario. Just because the belt is moving at the same speed, and the wheels might not be moving, doesn't mean that the plane is not moving forward relative to the ground....

 

[jelms]

This is true, but forward motion can be achieved in this scenario. Just because the belt is moving at the same speed, and the wheels might not be moving, doesn't mean that the plane is not moving forward relative to the ground....

relativity a great Einstein issue so if the ground, or the runway, is moving at the same speed of the plane, what is the speed of the air over the wing?

from a grounded person it is zero, and the plane will go no where.

did i not read enough of this. I kind of jumped in late

-jeff

 

[ntw0rk]

relativity a great Einstein issue so if the ground, or the runway, is moving at the same speed of the plane, what is the speed of the air over the wing?

from a grounded person it is zero, and the plane will go no where.

did i not read enough of this. I kind of jumped in late

-jeff

You read the same thing everyone else did, and jumped to the same conclusion.

 

[TREKER]

Why dont they just do an experiment with a smaller plance and see what happens. :dontknow:

My brain hurts from this. Plus who gives a shit really???

 

[nycstev]

This is true, but forward motion can be achieved in this scenario. Just because the belt is moving at the same speed, and the wheels might not be moving, doesn't mean that the plane is not moving forward relative to the ground....

Thats what I undrstood. If the plane is moving in the + direction @175mph
and the belt is moving in the - direction @ 175 mph how can the plane develop any motion relative to the ground ( or the air which is what it needs for lift)?

 

[ntw0rk]

Thats what I undrstood. If the plane is moving in the + direction @175mph
and the belt is moving in the - direction @ 175 mph how can the plane develop any motion relative to the ground ( or the air which is what it needs for lift)?

Because the wheels (which do nothing for providing thrust) will be moving and allowing the plane to move forward relative to the ground. Essentially, the wheels will be moving at 350 mph, but the plane can still move forward.

 

[Roz]

WHO BUMPED THIS THREAD?!?!?!

 

[faslane505]

heres one...a train is moving north at 2200ft per sec....you fire a gun south. the gun has a muzzle velocity of 2200ft per sec....asume weather conditions do not affect the bullet...wind, humidity, alt...etc. what happends to the bullet?

 

[ntw0rk]

heres one...a train is moving north at 2200ft per sec....you fire a gun south. the gun has a muzzle velocity of 2200ft per sec....asume weather conditions do not affect the bullet...wind, humidity, alt...etc. what happends to the bullet?

It falls to the ground.

 

[ntw0rk]

WHO BUMPED THIS THREAD?!?!?!

Didn't you see my pic on post no. 100?

 

[Roz]

Didn't you see my pic on post no. 100?

Hah! Nice!!!! :rock:

Oh, and the plane flies people.

 

[Roz]

heres one...a train is moving north at 2200ft per sec....you fire a gun south. the gun has a muzzle velocity of 2200ft per sec....asume weather conditions do not affect the bullet...wind, humidity, alt...etc. what happends to the bullet?

We're still on Part II, bastage!

More specifics please . . .

Am I on the train when I fire the gun? - Am I shooting at the train? If I am on the train, do I fire the fun inside on of the train's cars? Am I shooting out the window?

What happens if I am on the train and I fire the gun north? :dontknow:

 

[faslane505]

your firing out of the back of the train...while your on it

 

[faslane505]

We're still on Part II, bastage!

More specifics please . . .

Am I on the train when I fire the gun? - Am I shooting at the train? If I am on the train, do I fire the fun inside on of the train's cars? Am I shooting out the window?

What happens if I am on the train and I fire the gun north? :dontknow:

i would say that it is traveling at 4400fps

 

[MRXSRT]

heres one...a train is moving north at 2200ft per sec....you fire a gun south. the gun has a muzzle velocity of 2200ft per sec....asume weather conditions do not affect the bullet...wind, humidity, alt...etc. what happends to the bullet?

The damn bullet will hit the treadmill and launch the freaking plane into the air FINALLY!

 

[Black1]

The damn bullet will hit the treadmill and launch the freaking plane into the air FINALLY!

LMFAO!!!! :congrats:

 

[AWDisuzu]

WHAT??? That's wrong. There is no shaft from the engines to the wheels.

The friction of the moving conveyor belt does not act upon the forward motion of the aircraft, because the aircraft is pushing itself forward against the air, not against the conveyor.

that's like saying a wind powered boat or a sailboat cannot push itself against the current.

If airplanes relied on thrust from the engines pushing it's tires against the ground, then water planes would not be able to fly either.

Right. But the thrust from the engines is transferred to the wheels which provide the leverage.

 

[ntw0rk]

WHAT??? That's wrong. There is no shaft from the engines to the wheels.

The friction of the moving conveyor belt does not act upon the forward motion of the aircraft, because the aircraft is pushing itself forward against the air, not against the conveyor.

that's like saying a wind powered boat or a sailboat cannot push itself against the current.

If airplanes relied on thrust from the engines pushing it's tires against the ground, then water planes would not be able to fly either.

The sailboat analogy is perfect!!!!:congrats::congrats: