brobradh77 Posted December 14, 2006 Report Share Posted December 14, 2006 Your engineering professor either did not understand the question or he is a total fool. Let me ask you this, if the dam plane is flying in the air with its wheels up, not down, what the hell is providing the force? DUH, the turbines or props!!! The turbines act as a force on the air and the plane, not the tredmill. Also, if the plane sits still on the tredmill, whats th tredmills speed? Duh...ZERO. So inorder for the tredmill to have speed, so must the plane!!! Hello...not rocket science folks. God I hope someone of you never become engineers...no wonder a bottle of medication is so dam hard for an adult to open...lol. <{POST_SNAPBACK}> Your right after reading that I dont even know why planes have wings since you obviously dont need them to fly just turbines. Maybe he didnt understand what I was telling him who knows he seemed to have a grasp when he stated the question back to me. But he made one thing clear yes the turbines provide the force/speed to propel the plane thru the air and down the runway but the wing design is what gets it off the gound. So please we may not all be as brilliant as you but you have no right to be calling anyone a fool. It was just an answer to a question that we all have different opinions about no need in name calling. Quote Link to comment Share on other sites More sharing options...
SSThunder Posted December 14, 2006 Report Share Posted December 14, 2006 I got a good one for you. What came first the chicken or the egg lol Anybody else have any real brain teasers? This one was fun last year. <{POST_SNAPBACK}> What about my question? Chicken or egg Quote Link to comment Share on other sites More sharing options...
SS--BLOWN Posted December 14, 2006 Report Share Posted December 14, 2006 (edited) My first answer, after much thought, was a HELL NO. Then it dawned on me. Step ONE: Admit that we’re car guys. I first imagined this scenario EXACTLY like putting a car on a dyno. Frictionless rollers cancel out acceleration so that wheels turning 90 mph and speedometer reading same still results in zero mph in the real world. Step TWO: Reread the riddle. It says that whenever the plane gains speed, the conveyor accelerates to match the speed. If the plane isn't moving, the belt isn't moving. Once the jets start thrusting and the plane gains speed, the belt moves at the same speed/opposite direction. Get it? If the plane is MOVING 90 mph, then the belt has accelerated to 90 mph in the opposite direction. It doesn’t stop the plane from moving—the jets are still thrusting and there is nothing stopping or counteracting that thrust. It’s just that the wheels against the belt are not like the car on the dyno. There is no forward torque or other resistance behind them--they are freewheeling. The wheels are simply being ARTIFICIALLY accelerated to twice the speed the airplane is moving. In reality, the plane is moving 90 mph but if the wheels were hooked up to a speedo, it would read 180. The plane would take off but the wheels would be rotating twice as fast as they otherwise would need to be. Edited December 14, 2006 by SS--BLOWN (see edit history) Quote Link to comment Share on other sites More sharing options...
Black2003SS Posted December 14, 2006 Author Report Share Posted December 14, 2006 SS-blown has got it nailed down. There are no opinions in engineering. We deal in straight facts and when facts are not available, we deal in theories. Theories become law once proven to have no exceptions and hold true in every case. Sorry about the name calling, I forgot my sensitivity meds today. The bottom line is it 100% assumed that the plane has wings for lift. And it is 100% assumed there is no head wind. Head wind has nothing to do with it in this case. Your professor isnt a total fool...but he's still wrong by stating the plane can not take off in this scenario. Quote Link to comment Share on other sites More sharing options...
brobradh77 Posted December 14, 2006 Report Share Posted December 14, 2006 SS-blown has got it nailed down. There are no opinions in engineering. We deal in straight facts and when facts are not available, we deal in theories. Theories become law once proven to have no exceptions and hold true in every case. Sorry about the name calling, I forgot my sensitivity meds today. The bottom line is it 100% assumed that the plane has wings for lift. And it is 100% assumed there is no head wind. Head wind has nothing to do with it in this case. Your professor isnt a total fool...but he's still wrong by stating the plane can not take off in this scenario. <{POST_SNAPBACK}> Its cool about the name calling I figured you just needed a hug today and didnt get one . I guess it is a good thing I am a mechanical engineering major and not an aerospace engineering major Anyway I appreciate reading your takes on this it has been very informative and hey as an engineer you learn somthing new every day. Quote Link to comment Share on other sites More sharing options...
Black2003SS Posted December 14, 2006 Author Report Share Posted December 14, 2006 I hated statics, dynamics, and calculus. I have no idea how I ever got through them. I hated electrical circuits more though...geez. Now thermodynamics I understood real well for some reason....who knows. Quote Link to comment Share on other sites More sharing options...
Kim Posted December 14, 2006 Report Share Posted December 14, 2006 To SSThunder's ?..... Since both the chicken and the egg create the other in certain circumstances (a chicken emerges from an egg; an egg is laid by a chicken) it is ambiguous which originally gave rise to the other. Purely logical attempts to resolve the dilemma result in an infinite regress, since an egg was caused by a chicken, which was caused by an egg, etc. Since every chicken originates from its egg, it seems obvious the egg came first. Put simply, the reason is down to the fact that genetic material does not change during an animal's life. The solution may require an examination of syntax and may rely on verification from advances in modern genetic science. When used in reference to difficult problems of causality, the chicken and egg dilemma is often used to appeal to the futility of debate and lay it to rest. It's hard being smart Not really.....I love Wikipedia.com Quote Link to comment Share on other sites More sharing options...
misterp Posted December 14, 2006 Report Share Posted December 14, 2006 ... When used in reference to difficult problems of causality...You start talking about time travel and so help me god I am going to scream. Quote Link to comment Share on other sites More sharing options...
Kim Posted December 14, 2006 Report Share Posted December 14, 2006 ... When used in reference to difficult problems of causality...You start talking about time travel and so help me god I am going to scream. <{POST_SNAPBACK}> You should watch Donnie Darko After thinking some more about the chicken and the egg.....The chicken came first, because if the egg was first, who kept it warm????? Quote Link to comment Share on other sites More sharing options...
Black2003SS Posted December 14, 2006 Author Report Share Posted December 14, 2006 Time travel IS possible in relative to light anyways. Theoretically, if you left earth in a spaceship, knowing exactly what the speed of light travels, you could leave earth at a greater than speed of light and go into space to the point of time you wanted to view. But say if you could travel at 1 million times the speed of light, you could see what was happening to the earth years ago. We view stars millions of light years away and the light we are viewing in the telescopes and seeing in the sky are a history of what happened hundreds and even thousands of years ago. That is why scientists are trying to study stars further and further away. The further away the star is, the longer ago the event they witness happened. Sort of time travel from a spectators point of view, not participants. Of course logistics of having a telescope powerful enough to see back to earth are irrelevant. Also, traveling at the speed of light theorizes that one would travel into the future. Of course it is all theory. Quote Link to comment Share on other sites More sharing options...
brobradh77 Posted December 14, 2006 Report Share Posted December 14, 2006 I hated statics, dynamics, and calculus. I have no idea how I ever got through them. I hated electrical circuits more though...geez. Now thermodynamics I understood real well for some reason....who knows. <{POST_SNAPBACK}> Really I guess I am white and nerdy..lol I enjoyed those classes and I have decided to add math as my minor because all I lack is 1 class so I guess I will take linear algebra I am sure as an engineer I could find that useful since I just got out of differential equations and laplace transforms. Are you a mechanical engineer? Quote Link to comment Share on other sites More sharing options...
56chevywagon Posted December 14, 2006 Report Share Posted December 14, 2006 It is a trick question. It states that the plane is standing on the conveyor but it does not state that the plane is stationary...so the plane will still move down the runway like normal therefore it will have airspeed and lift at the wings. I talked to one of my engineering teachers about this problem today. He said the plane will not take of unless the wind conditions are right. He said the turbins give the power for take off and that doesnt depend on wheel speed BUT the design of the wing is what makes a plane able to lift off. It is designed for the pressure on the bottom of the wing to be greater than on top of the wing which can be adjusted by the rutters. Unless that pressure on the bottom gets to that point from the resistance of the air flowing against it it will never be able to take off unless the headwind is strong enough to reach the point needed for lift off. <{POST_SNAPBACK}> No one said anything about wind. It only states that it's on a treadmill there for it will take off and no one said anything about the wings being different. This is a conventional plane we are talking about here. So yes it will take off! <{POST_SNAPBACK}> Right I know there was nothing menntioned about wind. I was stating that he told me unless there is that high amount of head wind it wont lift off due to the plane is basically just sitting still. Second as far as wings go all wings for any plane from conventional to commercial are all designed to do the same thing and lift the plane. They work on the principle of pressure under the wind is great enough for lift. He explained all this better but he did do some engineering research in aeronautics. <{POST_SNAPBACK}> Quote Link to comment Share on other sites More sharing options...
Black2003SS Posted December 14, 2006 Author Report Share Posted December 14, 2006 I was...lol. Hated it. Now I am in finance. Pays more. Much more. Funny thing. When I got out of college and into the job market, I was a ABS/traction control engineer at TRW and I didnt use 90% of the stuff I learned in college. Basically anyone who knew basic physics, basic programming could have done 905 of the jobs there. Anytime a new system required a new algorithm, they had some asian or indian guy in a padded room come up with it. Quote Link to comment Share on other sites More sharing options...
misterp Posted December 14, 2006 Report Share Posted December 14, 2006 It is a trick question. ... THANK GOD FINALLY the voice of reason! Mr. P. Quote Link to comment Share on other sites More sharing options...
brobradh77 Posted December 15, 2006 Report Share Posted December 15, 2006 I was...lol. Hated it. Now I am in finance. Pays more. Much more. Funny thing. When I got out of college and into the job market, I was a ABS/traction control engineer at TRW and I didnt use 90% of the stuff I learned in college. Basically anyone who knew basic physics, basic programming could have done 905 of the jobs there. Anytime a new system required a new algorithm, they had some asian or indian guy in a padded room come up with it. <{POST_SNAPBACK}> lol damn asians.. finance must pay well from the job market around here just a bachlor in mechanical engineering starts any where from 90-120k in like Dallas and like 60-70k in small cities. Quote Link to comment Share on other sites More sharing options...
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