Guest " " Posted January 4, 2011 Share Posted January 4, 2011 It depends on how the airplane derives forward motion. If the forward motion is derived by the rotation of wheels exclusively, it will never take off, since there is no forward motion. if the forward motion is derived by the thurst created by the propeller, or the thrus created by other means, it will take off once the lift created on the top surface of the wings exceeds the weight of the airplane. reguardless of what the wheels are doing. Quote Link to comment Share on other sites More sharing options...
BigCliff Posted January 4, 2011 Share Posted January 4, 2011 You need airspeed to create lift to create flight. No airspeed if the plane is standing still unless the wind is blowing straight into the plane at a velocity enough to create lift. Now things might change if you are talking about rocket purpulsion and the force created by the change in mass of the burning of fuel which is a little over my head. Check it out: http://www.braeunig.us/space/propuls.htm Quote Link to comment Share on other sites More sharing options...
oldenough Posted January 4, 2011 Share Posted January 4, 2011 For this argument it does not matter whether you are talking about "rocket" propulsion, "rubber-band" propulsion, or "clock-work" propulsion. Hell... you could even use pedal power, you'll still take-off. I thought this myth was put to bed after myth-busters shot it down in flames. But then it should not have taken a tv episode to show a principle that most kids flying a model plane in the park understand.[] Quote Link to comment Share on other sites More sharing options...
jacksonbart Posted January 4, 2011 Share Posted January 4, 2011 its does take off chief! Quote Link to comment Share on other sites More sharing options...
Coytee Posted January 4, 2011 Author Share Posted January 4, 2011 its does take off chief! Could have been trick photography.... I once saw my brother in laws cat.... it had some feathers stuck to its lips. It was framed. We all know the dog glued the feathers to the cats lips to take the suspicion away from the dog. It's all about obfuscation Quote Link to comment Share on other sites More sharing options...
BigCliff Posted January 4, 2011 Share Posted January 4, 2011 its does take off chief! The plane is moving in relationship to the ground, you can see it moving past the cones. Quote Link to comment Share on other sites More sharing options...
BigCliff Posted January 4, 2011 Share Posted January 4, 2011 The original post said: "conveyor has a system that tracks the speed of the plane and matches it exactly in the opposite direction."! That plane was moving forward so the conveyor was not matching the speed of the plane. Quote Link to comment Share on other sites More sharing options...
sheltie dave Posted January 4, 2011 Share Posted January 4, 2011 Cliff, some people will not look at the question as a system, and will miss anything they do not want to see. They will not comprehend what a net zero vector is, or what it means. It would be slightly different if the jet were a Harrier. Quote Link to comment Share on other sites More sharing options...
oldenough Posted January 4, 2011 Share Posted January 4, 2011 How so different??? The net result is they would both TAKE-OFF. Cliff, some people will not look at the question as a system, and will miss anything they do not want to see. They will not comprehend what a net zero vector is, or what it means. It would be slightly different if the jet were a Harrier.[] Quote Link to comment Share on other sites More sharing options...
sputnik Posted January 4, 2011 Share Posted January 4, 2011 Noooooo, not again! For exhuming this thread, I hate all of you with an intense passion that mere words cannot begin to express. It takes off Quote Link to comment Share on other sites More sharing options...
BigCliff Posted January 5, 2011 Share Posted January 5, 2011 Cliff, some people will not look at the question as a system, and will miss anything they do not want to see. They will not comprehend what a net zero vector is, or what it means. It would be slightly different if the jet were a Harrier. Agreed Dave, I have said my piece and I think it is time to "exit stage left" as Snagglepuss would have said. Yes a Harrier as well as a Helicopter would fly. Quote Link to comment Share on other sites More sharing options...
Cal Blacksmith Posted January 5, 2011 Share Posted January 5, 2011 I can't beleive that this thread has been dug up! I posted before and will say the same again here. Yes it will take off and fly away. The thing people have a hard time understanding is that the wheels on an aircraft only hold it up off the ground. It does not propell it's self with the wheels, if it did, once it took off, it would loose speed and fall from the sky. The aricraft, large, small, jet, prop.... whatever pushes against the air. The wheels don't do anything but turn, thus, it does not matter what the ground is doing (or tread mill) you are not affecting the source of propulsion, the air. So Yes, the prop or jet or rubberband will still pull the aircraft forward, it will still gain speed and once the wings get enough airflow, it will take off, leaving the treadmill on the ground while the aircraft flys away. Quote Link to comment Share on other sites More sharing options...
Cal Blacksmith Posted January 5, 2011 Share Posted January 5, 2011 Cliff, some people will not look at the question as a system, and will miss anything they do not want to see. They will not comprehend what a net zero vector is, or what it means. It would be slightly different if the jet were a Harrier. It is not a zero sum question. It is a word play, people relate to pushing on the ground to get forward motion, aircraft don't. If you tied the aircraft to the treadmill by cables so the aircraft could not move independent of the treadmill, then as long as the force of the treadmill is equal and oposite to the thrust of the aircraft, the aircraft will not move, nore will the treadmill, both will remain staitonary because, if the aircraft is not moving, the convyer will not be moving, thus matching the "speed" of the aircraft. In effect, you will be tying the aircraft down to one spot and in THAT situation, NO ammount of force, short of breaking the cables, will allow the aircraft to move. HOWEVER, once you break the cables and let the aircraft move under it's own power, regardless of what the ground is doing, it will, given enough room, acclerate to V min and take off. How about putting it a different way. You are sitting on a bicycle, being pulled by a car at 10 MPH. There is a treadmill under ONLY the bicycles wheels, not the cars wheels. If the car is moving at 10 MPH and the treadmill is moving 10 MPH the other way under the bicycle, the wheels on the bike will be turning at 20 mph but you will still be going forward at 10 MPH. It is NOT a net zero vector question, it is a clever word play designed to cause confusion. Quote Link to comment Share on other sites More sharing options...
BigCliff Posted January 5, 2011 Share Posted January 5, 2011 This is the last I will have to say. X=speed of plane Y=speed of conveyor Y= -X because conveyor speed will be the same as plane speed but in the opposite direction Therefore the speed of the plane plus the speed of the conveyor would be X+Y or X+ (-X) which will be 0 so the plane will travel 0 as in zero mph or what ever speed you want to use. No speed no lift no takeoff. Quote Link to comment Share on other sites More sharing options...
oldenough Posted January 5, 2011 Share Posted January 5, 2011 This is the last I will have to say. X=speed of plane Y=speed of conveyor Y= -X because conveyor speed will be the same as plane speed but in the opposite direction Therefore the speed of the plane plus the speed of the conveyor would be X+Y or X+ (-X) which will be 0 so the plane will travel 0 as in zero mph or what ever speed you want to use. No speed no lift no takeoff. Whether it's the last thing you say or not...you are completely WRONG Einstein.[]X+Y=Z Quote Link to comment Share on other sites More sharing options...
BigCliff Posted January 5, 2011 Share Posted January 5, 2011 This is the last I will have to say. X=speed of plane Y=speed of conveyor Y= -X because conveyor speed will be the same as plane speed but in the opposite direction Therefore the speed of the plane plus the speed of the conveyor would be X+Y or X+ (-X) which will be 0 so the plane will travel 0 as in zero mph or what ever speed you want to use. No speed no lift no takeoff. Whether it's the last thing you say or not...you are completely WRONG Einstein.X+Y=Z Yes and according to Einstein the faster(Speed) you travel the slower time will move so if you are sitting in that plane time is the same for you as it is for everyone else standing still at zero velocity. Quote Link to comment Share on other sites More sharing options...
sputnik Posted January 5, 2011 Share Posted January 5, 2011 *snert* Ha. heehee. oh geez . . . bwhahaha . . . BWAAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA . . .*gasp* . . . hahahhahahahahahahahahahahahahahahahaHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAAAAAAAAAAAAAAAAAAAAAAA!!! whew Quote Link to comment Share on other sites More sharing options...
Rich_Guy Posted January 5, 2011 Share Posted January 5, 2011 The original post said: "conveyor has a system that tracks the speed of the plane and matches it exactly in the opposite direction."! That plane was moving forward so the conveyor was not matching the speed of the plane. Yes but the planes wheels have nothing to do with its speed, the plane uses air to both accelerate and to get lift and it will accelerate through the air thus it will gain speed (and must gain speed to fly) the conveyor will simply make the wheels spin faster not prevent the plane from either accelerating or flying. Quote Link to comment Share on other sites More sharing options...
BigCliff Posted January 6, 2011 Share Posted January 6, 2011 Put more friction on the plane's contact to the conveyor and use ski skids no wheels. The premise behind this is that the conveyor will move at a speed fast enough to keep the plane motionless with regards to its surroundings. That being said, the conveyor, even with wheels on the plane, would be moving at an increasing great velocity(too fast to imagine). Once that conveyor reaches the speed of light(671,000,000MPH), which according to Einstein is maximum velocity, then the plane would begin to move forward and be able to fly. Then the real question is what would happen to the conveyor, for one it would be frozen in time. Quote Link to comment Share on other sites More sharing options...
Rich_Guy Posted January 6, 2011 Share Posted January 6, 2011 Put more friction on the plane's contact to the conveyor and use ski skids no wheels. The skids would likely even prevent a plane from flying even on a typical runway without the conveyor. However a planes wheels are free floating and have little impact on its acceleration speed which it gets through the air by propeller or jet. So while the conveyor will make the planes free floating wheels need to spin faster, the plane will still accelerate and then fly through the air. I watched the entire Mythbusters episode and with both model scale and the real plane the conveyor had no effect at all on the planes ability to fly. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.