RichR
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Registered: 17th Oct 01
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quote:
Originally posted by Steve
quote:
Originally posted by LiVe LeE
yes but on the fucking ground the relative airspeed and ground speed will be the fucking same - on the conveyor, the airspeed will be zero, the ground speed will be the wheel speed
of course the fucking wheels have an effect on the forward speed - they do not simply freewheel; as they are in contact with the ground - only when the wheels leave the ground does the acceleartin force and lift produced become greater than that required to keep the plane in equilibrium
however this wont occur on a conveyor as the two will just keep increasing in speed and contact will never be lost
in the conveyor situation, the ground speed will increase due to the wheels turning faster over the conveyor, howver the airspeed will show as similar to if the plane were accelerating on a stable surface. Soon youl click and youl realise that your wrong. You just looking at it from the wrong angle
no if the plane has no forward motion ( which it wont if the wheels remain incontact with the conveyor and the conveyor continues to move at the same velocity but opposite direction) it will not have any air speed - the air speed will be zero
airspeed is measured relatrive to the air through which you are travelling - if you're not travelling through air(whihc when stationary you wouldnt be) then there is no air speed
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Hammer
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i'll try and make it as simple as possible here, people are becoming rather frustrated 
get 2 pieces of wood and place a tin of beans in between them.
the bottom piece of wood is the conveyor and the top piece is the aircraft, the tin represents the wheels of the plane.
now as in the question states, thrust both pieces of wood (the conveyor and the plane itself) equally and in an opposite direction.
does the plane stay in the one place? no it doesnt it moves forward and the tin (the wheels) spin more due to the conveyor moving, thats all that happens.
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3CorsaMeal
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The point of the riddle is that the motion of the wheels exerts only a minor frictional force opposing the forward movement of the plane. The major force being supplied is from the plane engine, and that force is a forward force. The net force is equal to the forward force minus the negligible frictional force. This obviously produces a net forward force. Therefore, the plane moves forward, regardless of how much the wheels are spinning. The plane is not remaining stationary on the conveyor belt becasue there is a force acting on the plane that is not dependent on the motion of the conveyor belt.
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Steve
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Registered: 30th Mar 02
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 i think you need a certain type of logical thought to work it out
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RichR
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but the wheels are attached to the plane you tit - the "bean can" wouldnt remain in the same place in relation to the top plank would it numpty
the wheels on the plane are attached to the fucking plane - they dont move backwards do they
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John
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Registered: 30th Jun 03
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People are looking at this as if the wheels are providing the thrust.
The wheels will just spin faster and faster.
Anyway i've got an exam to go to, I hope this has been settled when I return.
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3CorsaMeal
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http://txfx.net/2005/12/08/airplane-on-a-conveyor-belt/
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Steve
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it was settled earlier 
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RichR
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if there is no forward motion between the wheels and the conveyor; how can there be forward motion between the plane and the ground - the two are attached
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Steve
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fucking thank you 3cm
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Steve
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read what 3cm posted
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John
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Registered: 30th Jun 03
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It would definetely move, the wheels will just spin increasing faster.
I think there is some frantic googling going on here to try and prove an incorrect point.
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Steve
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another quote that explains perfectly
"The landing gear are merely a way of eliminating (most of the) friction between the airplane and the runway. How fast the wheels are turning is meaningless. For instance, to take an example from real life, say the runway is coated with ice. The wheels will not be turning as fast as they would on a dry runway. In fact, on a perfectly frictionless surface, the wheel would not turn at all! The only thing that matters if how fast the airplane is moving through the air. The thrust generated by the plane moves the plane forward. The conveyor belt moving backwards spins the wheels backwards at twice their normal rate for that speed on a dry runway. So now the plane is moving forward at 100 knots and the wheels are spinning forward at 200 knots and the runway is moving backwards at 100 knots. So the wheels’ relative speed to the ground is 100 knots, the 100 knots generated by the airplane."
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Steve
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and another
"You can test this with a piece of paper and a matchbox car (which has free rolling wheels like an airplane… or like a car in neutral.) Place the paper on a table, and place the matchbox car on the paper. Take your hand, and hold the car still with a lightly placed finger on top of the car. At this point you are providing no forward thrust, and the “conveyor belt” is not moving. The car remains stationary. Now, continuing to hold the airplane with a lightly placed finger, and start to pull the paper out from under the car, in the backwards direction. According to Neal’s logic, the car should push back on your finger with the same force that you are exerting on the paper… but this is not what will happen. You will find that your lightly placed finger is not stressed to any noticeable extent. The paper will slide out, and the wheels will spin, but the car will not be propelled backwards. The reason for this is is that the rotation of the wheels is not related to the movement of the matchbox car except by the very small friction component of the axle, which your lightly placed finger can easily control."
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Hammer
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quote:
Originally posted by LiVe LeE
but the wheels are attached to the plane you tit - the "bean can" wouldnt remain in the same place in relation to the top plank would it numpty
the wheels on the plane are attached to the fucking plane - they dont move backwards do they
now your stupidity is getting me frustrated.
attach the bean can to the plane via a complex landing gear stucture in scale then, the exact same principle applies.
Are you doing a degree in ignorance?
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RichR
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the other bullshit analogy of the toy car doesnt add up - of course theres no noticable difference in resistance - the car weighs less than what 15 grams - a plane weighs hundreds of tonnes - you would see a huge difference
I knwo the aircraft propels itself via the movement of air - but when the aircraft is on the ground; it has to overcome the forces which are acting on it (which wouldnt be present wehn the plane is in the air)
the forces between wheel and conveyor would not be overcome if the two travel at equal and opposite speed
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Steve
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oh dear live lee, please after seeing all this i would have thought you would have seen, sadly you are beyond saviour
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Brett
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I do love how if you post a link to some tosspot on some blog it instantly means you're right
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Steve
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read it and think about it
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RichR
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do you believe everything posted on the internet? just because some guys said this; some guy said that? its bullshit - think about it logically
and SXi04 - grow up!
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Steve
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you need to think about it logically not us, we have it correct.
yes the matchbox car is only 15grams, and yes a plane is hundreds of tons, but the forces applied in both directions are all relative too
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Hammer
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quote:
Originally posted by LiVe LeE
do you believe everything posted on the internet? just because some guys said this; some guy said that? its bullshit - think about it logically
and SXi04 - grow up!
Ok sir, but please remember i was having an adult conversation with the big boys and you called me a 'tit' which i let slide.
Maybe you should do a wee bit of growing up?
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Jules S
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Registered: 24th Dec 03
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We should have stopped after my original post
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RichR
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but the differecne would be far more noticable - the percentage change required may stay the same - but the total difference would be huge by comparison and far more noticable
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Cybermonkey
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Registered: 22nd Sep 02
Location: Sydney, Australia
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quote:
Originally posted by Steve
you need to think about it logically not us, we have it correct.
yes the matchbox car is only 15grams, and yes a plane is hundreds of tons, but the forces applied in both directions are all relative too
POAH says:
post that the photo was taken at the hall of mirrors at the fun fair
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