A Wednesday conundrum
Discussion
omitchell said:
The plane will take off albeit with the wheels turning at double the speed that the plane is trvelling forwards, this is due to the fact the jet engines provide forward thrust to the airframe and not to the wheels and as such it is irelevant how fast the wheels are turning if at all, the plane will still accelerate regardless unless a force is applied to the plane itself
Hmm.. thrust will push the plane (like how you would push a car), which will cause the wheels to turn, the conveyor see's this and moves the plane backward be an equal amount in response. So the plane stays put.
the end!
:alice tinker modeon: Those poor pasengers whats going to happen to them if they cant take off and go on holiday ,that they have worked for the last year,and if they cant go on holiday then how are they going to be ready for the next years work and paying all their taxes.... :alice tinker modeoff:
Tyre Smoke said:
No, the plane cannot take off because all the force the jet engines produces is sent to the wheels which is counteracted by the converyor.
I really hope you are not a commercial airline pilot.
When did you last see a plane with a driveshaft to its wheels?
The force is transmitted, because when you push say a toy car, you are moving it forwards, but the ground will move backwards relative to the object you are pushing. This is what i mean by the wheels turning, sorry if i wasn't clear.
scorp said:
No, the plane cannot take off because all the force the jet engines produces is sent to the wheels which is counteracted by the converyor.
I really hope you are not a commercial airline pilot.
When did you last see a plane with a driveshaft to its wheels?
The force is transmitted, because when you push say a toy car, you are moving it forwards, but the ground will move backwards relative to the object you are pushing. This is what i mean by the wheels turning, sorry if i wasn't clear.
Nope. I'm not going to explain.
Hold me down.
Stop it.
Oh Feck.
The jet propulsion is pushing against the air behind the aircraft. It has nothing to do with the free spinning wheels of the plane. Apart from gravity, the wheels are largely irrelevent. What do you think the engines push against at 30,000 feet?
scorp said:
The plane will take off albeit with the wheels turning at double the speed that the plane is trvelling forwards, this is due to the fact the jet engines provide forward thrust to the airframe and not to the wheels and as such it is irelevant how fast the wheels are turning if at all, the plane will still accelerate regardless unless a force is applied to the plane itself
Hmm.. thrust will push the plane (like how you would push a car), which will cause the wheels to turn, the conveyor see's this and moves the plane backward be an equal amount in response. So the plane stays put.
the end!
you have to accept the fact the wheels are treated as if they provide no friction relative to the movement of the plane, your statement would be true if the brakes were locked on but otherwise my response still stands
scorp said:
Hmm.. thrust will push the plane (like how you would push a car), which will cause the wheels to turn, the conveyor see's this and moves the plane backward be an equal amount in response. So the plane stays put.
The plane will still continue to move, as the wheels are free-wheeling and hence the conveyor can move as fast as it likes in the other direction. The plane will still take-off.Moose. said:
Hmm.. thrust will push the plane (like how you would push a car), which will cause the wheels to turn, the conveyor see's this and moves the plane backward be an equal amount in response. So the plane stays put.
Ahh.. i see what you mean, now you explain it like that. This assumes there is zero friction at the wheels too
scorp said:
Wrong, planes at takeoff use thrust to get off the ground, the wings are ineffective at takeoff speeds.
WTF???
A planes speed is relative to the AIR around it, not the ground or the wheel speed.
it would take off, no problem at all. If you can't grasp this, imagine a piece of string tied to the front of the plane pulling it along the conveyor. You could still pull it forwards, but the wheels would be turning twice as fast.
HTH
Paul
Working for a major aircraft engine manufacturer....
scorp said:
Wrong, planes at takeoff use thrust to get off the ground, the wings are ineffective at takeoff speeds.
so why do they need a runway then? put the engine to max and it should shoot stright up into the air by that reckoning.
Inertia.
If the wings are "ineffective at takeoff speeds" as you say, then why do 'planes have wings at all? Why, in fact, is there any such thing as a "takeoff speed"?
Consider the fact that the takeoff ground speed is lower when taking off into a strong headwind (and for extra points, work out that the takeoff air speed is always the same regardless of wind)
I think you've somehow gotten yourself confused in a parallel universe where physics works in a completely different manner...
tiga84 said:
Aaaaaaaargh! Been done to death already!!
It wont take off as there is no lift surely as the plane is static.
Would a car with downforce generate any on a rolling road at max speed? No. Reverse of this principle surely.........
You're getting confused with ground and air in the same way that scorp is.
Car downforce is not a factor of ground speed, but of the airspeed passing over the bodywork, spoilers etc.
Even stationary in a field, a car is capable of producing downforce if a strong enough wind blows over it.
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