Plane on a Conveyor Belt

[the chopper]

Hey Eric you are bang out of order, those references about cows aint funny the way you put them, you do not know me and yet you try to mock me. All you have really done is expose a darker side of yourself which may put prospective clients off. clever move!!!  It is not easy exposing ones inability to get a concept easily but i aint afraid to learn the hard way and have fun with it. But you were not funny wee man!!!!!!!!!!!!!!!!!!

[iacas]

Originally Posted by the chopper

are you trying to isult me !!!!!!!!!!!!!!!!!!!!!!!1

No.

Originally Posted by the chopper

Hey Eric you are bang out of order, those references about cows aint funny the way you put them, you do not know me and yet you try to mock me. All you have really done is expose a darker side of yourself which may put prospective clients off. clever move!!!  It is not easy exposing ones inability to get a concept easily but i aint afraid to learn the hard way and have fun with it. But you were not funny wee man!!!!!!!!!!!!!!!!!!

Who is Eric? Gosh he seems to have ticked you off...

Did you not see the funny video clip from City Slickers? It was funny.

Edit: And the chopper can spend a week in timeout for making threats and a few other silly things. Oy. I re-read what I wrote, removed the part about how he was doing a fine job of insulting himself (it doesn't really make sense, but I meant it as "he's doing a fine job of making himself look bad by refusing to accept the truth"), and added a bit pointing out specifically what I thought was funny. Oy.

[CR McDivot]

This gets my vote as the buggiest of all topics.

My answer to the question shows (incompletely) in the headings of "New Content" and in the homepage sidebar - but not in the topic (neither the 2 page, the 3 page, nor the 5 page version).

Here we go again...

Air speed over the wings (airfoil) is what creates lift. Neither a prop nor jet engine can produce enough air movement over the entire surface of the airfoil to produce consistent lift sufficient to lift the aircraft, let alone sustain such.

Neither thrust nor wheel speed have any bearing (both cancelled by the conveyor). Only the speed of the airfoil through the air mass can create lift.

The airfoil is relatively stationary. The air mass is relatively stationary. The aircraft is on the ground simply because there is not enough movement of air mass through the airfoil.

Simple "hillbilly" aerodynamics!

And to think that there are "educated and certified" engineers on this forum...

[Golfingdad]

This gets my vote as the buggiest of all topics.

My answer to the question shows (incompletely) in the headings of "New Content" and in the homepage sidebar - but not in the topic (neither the 2 page, the 3 page, nor the 5 page version).

Here we go again...

Air speed over the wings (airfoil) is what creates lift. Neither a prop nor jet engine can produce enough air movement over the entire surface of the airfoil to produce consistent lift sufficient to lift the aircraft, let alone sustain such.

Neither thrust nor wheel speed have any bearing (both cancelled by the conveyor). Only the speed of the airfoil through the air mass can create lift.

The airfoil is relatively stationary. The air mass is relatively stationary. The aircraft is on the ground simply because there is not enough movement of air mass through the airfoil.

Simple "hillbilly" aerodynamics!

And to think that there are "educated and certified" engineers on this forum...

Thrust is not cancelled by the conveyor, it isn't affected at all. And wheel speed is doubled.  There's no drivetrain on an airplane, so the affect of the conveyor on the planes motion is zero.

(And I won't laugh at or mock anybody in this thread, btw, because if you go back to the first page or so, you'll see my original answer was wrong too :))

[CR McDivot]

Air mass in front of the airfoil is not affected significantly by thrust.

One cannot produce enough thrust either by a propeller on the wing, or by a jet engine below the wing to move the airfoil through the air mass (or the air mass through the air foil) to lift the aircraft unless the entire aircraft is moving at a sufficient speed through the air mass.

Can you thrust the entire mass of the aircraft instantaneously to the required 18 meters per second (or whatever is required by the weight of the aircraft and the efficiency of the airfoil) without structural (let alone human) damage?

If so, you have superceded Newton!

Edited October 18, 2015 by CR McDivot

[Missouri Swede]

Can you thrust the entire mass of the aircraft instantaneously to the required 18 meters per second (or whatever is required by the weight of the aircraft and the efficiency of the airfoil) without structural (let alone human) damage?

Instantaneously has nothing to do with it.

The thrust provided by the engine(s) moves the aircraft, wings and all, through the air, producing lift. This happens thousands (at least) of times each day. As GD said above, the thrust isn't canceled by the conveyor belt.

[CR McDivot]

Ahh, I see!

The aircraft moves forward on the infinite length conveyor while still firmly on the "ground" and accelerates relative to the actual ground (and the air mass) to lift off speed.

Where upon the the aircraft's tires blow from over speeding requiring a belly landing at the destination.

Trick question, and a good one!

[Golfingdad]

Ahh, I see!

The aircraft moves forward on the infinite length conveyor while still firmly on the "ground" and accelerates relative to the actual ground (and the air mass) to lift off speed.

Where upon the the aircraft's tires blow from over speeding requiring a belly landing at the destination.

Trick question, and a good one!

If not the tires, then the wheel bearings might just catch fire.

[CR McDivot]

My assumption (and it was a poor one) was that the aircraft would remain stationary relative to the actual ground, rather than overcoming the rather slight resistance of the rolling wheels against the conveyor.

Still bet the landing gear would give out before lift off.

[iacas]

My assumption (and it was a poor one) was that the aircraft would remain stationary relative to the actual ground, rather than overcoming the rather slight resistance of the rolling wheels against the conveyor.

Still bet the landing gear would give out before lift off.

The wheels would only be spinning twice as fast so I doubt they'd have any problem. Heck, some planes take off at only 25 MPH.

[colin007]

off topic question -

lets say i can throw a baseball fifty miles an hour (i can actually throw one a lot faster than that...probably over a mountain, but lets keep the maths simple).  and lets say im standing in the bed of a truck going 50 MPH.  if i throw the ball in the direction of travel, will i be able to throw it 100 MPH?  at least for the initial velocity? how fast can i throw it if i throw in the opposite direction that the truck is driving?

[iacas]

Yes*. Yes*. 0 MPH.

* I am ignoring the small amount of added air friction on your body and arm.

[boogielicious]

off topic question -

lets say i can throw a baseball fifty miles an hour (i can actually throw one a lot faster than that...probably over a mountain, but lets keep the maths simple).  and lets say im standing in the bed of a truck going 50 MPH.  if i throw the ball in the direction of travel, will i be able to throw it 100 MPH?  at least for the initial velocity? how fast can i throw it if i throw in the opposite direction that the truck is driving?

Same question but with a flashlight! You are moving very fast, let's say 10,000 mph. You turn on the flashlight and point it forward. How fast does the light leave the flashlight?

Note: you must understand relativity!

Edited October 30, 2015 by boogielicious

[dkolo]

Same question but with a flashlight! Note: you must understand relativity!

The flashlight will also go 0 mph if you throw it off the back of the truck, haha. 

[Gator Hazard]

Same question but with a flashlight! You are moving very fast, let's say 10,000 mph. You turn on the flashlight and point it forward. How fast does the light leave the flashlight?

Note: you must understand relativity!

It leaves the flashlight at the speed of light, as the light is leaving relative to the object (the flashlight).

I will go and duck in a corner now as I am sure I am wrong on this one.  I'm a finance guy not a physicist!!!

[dsc123]

Remember that light from a flashlight only travels at 80% of the speed of light, due to interference from the impurities in the glass used to make the bulb and the limitations of contemporary batteries. 

This is why telescopes cannot see far beyond our own solar system.

 

[Gator Hazard]

Remember that light from a flashlight only travels at 80% of the speed of light, due to interference from the impurities in the glass used to make the bulb and the limitations of contemporary batteries. 

This is why telescopes cannot see far beyond our own solar system.

 

 The question was not fair! Damn your trickeries!!!! :)

[iacas]

Remember that light from a flashlight only travels at 80% of the speed of light, due to interference from the impurities in the glass used to make the bulb and the limitations of contemporary batteries. 

This is why telescopes cannot see far beyond our own solar system.

Uhhhh…