Brain Teaser

Discussion in 'Off Topic' started by csmguitarman, Oct 25, 2007.

  1. csmguitarman

    csmguitarman New Member

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    Disagree. I am not saying that the plane is floating. what do wheels do for a plane. they remove the "situation of friction" that would be present if there were no wheels. what does a plane need to move as fast a possible across the ground. other than its engines it needs as little ffriction with the ground as possible. be it wheels skis grease what ever. the wheels are simply there to provide no resistance to the ground for forward movement. So if there is minimal resistance how can a treadmill no matter how fast it is spinning all of the sudden tranfer that resistance through wheels that are resistanceless.

    You said that a plane moves it self forward from the thrust relationship between the engine and the air. i did not see ground in that relationship equation so how can the moving ground aka the treadmill insert its self into that equation.

    Try this. get an aeronautical physics degree . then youll understand. this question was my senior research. do you think that if i was wrong that i would have recieved my degree.

    How many people have changed their mind from take off to not take off. none. everyone that changes their mind changes to take off.
  2. MBK2

    MBK2 New Member

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    See, Goyleinlove had it right...

    While on the ground, the cars' drive train & engine AND the planes jet engine are both 'propelling' it on the ground.

    Do you agree that in order for a car to move 100 yards forward, it must be propelled by the engine/drivetrain to roll the 100 yards.

    And Do you agree that in order for a plane to move 100 yards forward, it must be propelled by the jet engine to roll the 100 yards??

    Your comparison of the car and the plane would apply if they were both simply free-floating to begin with...but they are not because of gravity.
  3. goyleinlove

    goyleinlove New Member

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    You say that the treadmill is moving the same speed as the plane but not the same speed as the wheels. Maybe I am missing sometheing but those two things are the same. Given that the plane is on the ground and moving the opposite direction of the treadmill at the same speed...the wheels have to be moving that speed or the whole question is void.

    Set aside car talk. Set aside torque, burning rubber, size of motor and everything else except the fundamental facts. A jet can not take off from a standstill regardless of any variables (with the exception or the aforementionted Harrier). When I say standstill I mean exactly that. In the stated scenario the plane is not physically moving from its given position. Therego, again...No forward MOTION...No possibility of flight.

    Birds=Yes
    Jets=No

    Unfortunately, we aren't cool enough to have mocked bird technology to that degree yet
  4. csmguitarman

    csmguitarman New Member

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    I do agree. but would you agree that their methods of being propelled are different. car=across ground plane= through air just rolling on ground
  5. MBK2

    MBK2 New Member

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    So if I applied massive brakes to that non-consequential wheels of the plane, the plane would still move forward on the ground??

    See, you're now getting angry again...
    What you are trying to say is that the jets engine will ROLL the plane over the treadmill faster than the treadmill would be going in the other direction.

    If that is what you're saying then your first post was completely misleading.

    If you wrote that thesis as your senior project, what was the conclusion or summation??
  6. csmguitarman

    csmguitarman New Member

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    Nope

    Since the wheels are free spinng, they essentailly ''disconnect'' the plane from the ground. No dont mean it floats. they are the path of least resistance for a plane to travel along the ground. If you apply breaks the wheels are now not free spinning.

    Sorry i am not getting mad. Just frusterated that this isnt making sense to you. Its one of those things that once understood makes ya feel dumb that you thought of it a different way. please note i was not calling you yourself dumb.
  7. csmguitarman

    csmguitarman New Member

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  8. MBK2

    MBK2 New Member

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    So if the wheel is so free-wheeling, then if the treadmill is going 100 mph in reverse and the jet isn't powering forward, will the plane just sit in place??

    Your original question is this...

    Now if you are changing the circumstances to suit your needs, then the whole thing is completely moot.........


    As for the feeling dumb comment...
    I know I'm right based on your initial question, so I'm not worried...

    It's you who claims to be an aeronautical engineer, and can't grasp physics of gravity, lift, & flight. Sorry to say.
  9. csmguitarman

    csmguitarman New Member

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    They are not. Without a treadmill the wheels travel the speed the plane is. The ground is moving at 0 and the plane at 100mph. 100+0=100. if the ground is moving the speed of the plane then the wheels have to speed up to accomodate both directions of travel so it goes from 100+0=100 to 100+100=200
    If the ground was moving with the plane the equation would be 100-100=0 this equation gives you the wheels speed. hope that helps.
  10. csmguitarman

    csmguitarman New Member

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    Which can move forward and why. a car on ice or a plane on ice. please dont say both. assume no friction between tires and ice
  11. goyleinlove

    goyleinlove New Member

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    Now you are mixing variables. The new tow truck scenario is completely diffrerent because the truck isn't affected by the speed of the conveyer.

    That is the same as saying that you can pull a wheelchair off a conveyer at an airport by speeding up. No shit! Nobody would dispute that. The original post is one of two things. It is either worded completely wrong, or the answer you gave is completely wrong. You have to include all variables initially. We don't know what you actually meant if it isn't what you actually wrote (assuming that the question was grossly misworded)

    Not trying to be pissy here but you are getting upset because you aren't able to either a) explain yourelf properly or b) admit that you are wrong.

    Given the specific deails of the op, if that was given by a student to me (as a professor) they would have to fight for the right to stay in my class.
  12. csmguitarman

    csmguitarman New Member

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    correct. my original post says the planes speed not the wheels. the wheels are not powered. your car measures speed by the wheel cuz the wheels are powered. you measure what is being moved. If a plane is on skis you cannot use wheel spin to detirmine speed. the use engine speed to detirmine that
  13. MBK2

    MBK2 New Member

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    You know that makes absolutely no sense whatsoever to the question, don't you?


    Lets say that the tow truck is pulling the plane at 100 mph (the plane now, doesn't matter about the tow truck), in your initial question, you state that the treadmill would
    match that 100 mph. Would the tow truck then be able to pull the plane off the front of the treadmill???????
    I really can't believe you're saying that.
  14. MBK2

    MBK2 New Member

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    You're completely right, he is trying to change what he initially asked.

    And I agree.....No Shit!!! LOL :tounge::laugh2::2cool:
  15. csmguitarman

    csmguitarman New Member

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    You are getting it. the tow truck isnt affected by the treadmill. perfect. now think of how a plane moves forward period. BY PULLING ITS SELF THROUGH AIR WHETHER ON GROUND OR IN AIR. the plane is pulling through air also cant be affected by the treadmill.

    If your theory was true then why dont the use treadmill for when planes land. just match the speed to the speed the plane is flying and the plane will stop dead in its tracks
  16. csmguitarman

    csmguitarman New Member

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    so are you saying the tow truck cant move.
  17. goyleinlove

    goyleinlove New Member

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    I see the logic you are using guitarman. But it doesn't reflect the orginal wording of th question and I think that is what caused the disagreements all around. I don't know that we even disagree on this in reality or if everyone just doesn't follow your meaning on some things because of the changing variables and the wording (which I am sure read perfectly to you because you were familiar with what you meant).
  18. MBK2

    MBK2 New Member

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    So if the plane speed is 10 mph forward and the treadmill speed is 10 mph rearward, you're trying to say that the plane would still float forward??

    So if the plane travels for an hour forward along the ground, it would be farther than 10 miles from the original spot??
  19. csmguitarman

    csmguitarman New Member

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    IT DOES NOT FLOAT. HOW MANY TIMES ARE GOING TO SAY THAT. THE PLANE ROLLS DAMMIT.
    I am saying that the plane rolls forward at 10mph and the treadmill at 10 mph back. and the wheels at 20.

    And yes after an hour it would be ten miles away.

    Think of this. There is a rope tied to a post at the end of the runway. It is not affected by the treadmill the same way air is not. Now sit on a skate board. Now pull yourself forward like the plane pulls though air. you telling me you can pull on the rope but stay in the same place.
  20. csmguitarman

    csmguitarman New Member

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    No its not the same. because the force you would apply goes directly into the wheels. A plane applies its force the air.

    That is what i am trying to get you to understand. planes and cars apply force differntly to different things.

    Again as you already answered. Why can a car with wings not maintain lift. Because it does not posess the ability to move air like a plane does

    Pretend that you are in that wheel chair at the airport. Now what if you could "grab and pull air" the way a planes engine does. you could pull your self along.

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