G
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Okay ... let's hear it - Fly or No Fly!
Poll closes at 8PM EST - 1 hr before the Mythbusters Show!
JR
Poll closes at 8PM EST - 1 hr before the Mythbusters Show!
JR
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Help Support Professional Engineer & PE Exam Forum:
cement
gray haired dude
I done been to the FAA Academy in OK City. Unless there is wind over the wing, it is a doorstop.
Desert Engineer
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My vote is that the plane will take off.
Since, the plane is not tethered to the ground, so it should only have to overcome the additional rolling resistance to take off. The only change should be that the wheels will roll at airplane speed plus treadmill speed. If the plane used its wheels to power the takeoff then you would have a problem.
Since, the plane is not tethered to the ground, so it should only have to overcome the additional rolling resistance to take off. The only change should be that the wheels will roll at airplane speed plus treadmill speed. If the plane used its wheels to power the takeoff then you would have a problem.
cement
gray haired dude
the wheels are a distractor.
FusionWhite
Epee ~)----- Fencer
SuperAlpha
Electronics Design Engineer
Thrust from the engines is what causes the plane to move. The moving air across the wing causes lift.
Now what part of that involves ground speed or wheel speed?
The wheels are there simply to keep it raised off the ground and able to roll.
Now what part of that involves ground speed or wheel speed?
The wheels are there simply to keep it raised off the ground and able to roll.
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Capt Worley PE
Run silent, run deep
The wheels and the treadmill would be moving at a furious rate!
DVINNY
2-time 10K winner
WHere were you two back at the beginning of the montrosity known as "riddle me this batman" thread??
well said BTW
Wolverine
Uncanny Pompadour
The question is dividing by zero. It's an infinite feedback loop.
As soon as the plane has groundspeed of 0+, the conveyor reacts to counter that speed through friction in the wheel bearings. At anything 0+ knots, the conveyor moves up to infinity.
Somewhere prior to infinity, the wheelbearings explode. Unless you install magical frictionless wheel bearings
The only way to make the plane take off is to push it backwards slightly. Then it will immediately pop into the air.
As soon as the plane has groundspeed of 0+, the conveyor reacts to counter that speed through friction in the wheel bearings. At anything 0+ knots, the conveyor moves up to infinity.
Somewhere prior to infinity, the wheelbearings explode. Unless you install magical frictionless wheel bearings
The only way to make the plane take off is to push it backwards slightly. Then it will immediately pop into the air.
IlPadrino
Well-known member
No conveyor known to man is capable of countering the speed through friction in the wheel bearings (aka axle friction) or tires (rolling resistance). Or at least that was implied by Fact 4 (Rolling resistance is a function of [what?] and axle friction is a function of [what]?"; the rolling resistance and axle friction of an airplane is orders and orders of magnitude less than the thrust provided) in the thread Riddle me this batman, (airplane-conveyor thread).
Sschell
Dude?
this depends on the phrasing of the challenge, my understanding is that the treadmill moves backwards at the same speed as the plane's wheels roll forward.... not a a speed fast enough to to counter the speed through friction... don't overcomplicate!
Anyways, we live in a univerise governed by physics... your conveyor belt will have a top speed.
If the top speed is not fast enough to burn up the wheel bearings, we have forward motion and therefore flight.
If that top speed is fast enough to burn up the bearings, the thrust from the engine will overcome the friction between (the no longer rotating) tire and the (hauling ass) conveyer, thus forward motion, thus flight!
DVINNY
2-time 10K winner
The plane will take off, it has no horizontal resistance keeping it from doing so, as long as the wheels spin freely.
I highly suspect that anyone stating the plane will just sit there, is simply stating that to get the arguement stirred up.
I highly suspect that anyone stating the plane will just sit there, is simply stating that to get the arguement stirred up.
cement
gray haired dude
if it is just sitting there, how is there wind flow over the wing? A helicopter or a Vertical Take Off aircraft have downward thrusting force for lift (actually a helicopter is a spinning wing, but we can save that for another day) but a traditional fixed wing aircraft has it engine provide thrust parallel to the ground. it needs to move forwad for the wing to achieve lift. the conveyor belt in theory prevents forward movement, so there is no airflow over the wing.
if they do the stunt correctly, the airplane will not take off. seriously.
but the dragging a tarp to replace a conveyor belt I see on the preview looks pretty sketch to me.
here it is Visit My Website
if they do the stunt correctly, the airplane will not take off. seriously.
but the dragging a tarp to replace a conveyor belt I see on the preview looks pretty sketch to me.
here it is Visit My Website
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DVINNY
2-time 10K winner
DVINNY
2-time 10K winner
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cement
gray haired dude
I don't know what those toys are doing there buddy. most likely what will happen is the conveyor will start bouncing at high speed, or will max out and the airplane will creep off the end and fall off because it is going too slow to fly.
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