Pjturbo
Well-known member
This thread proves that old saying,"Half the population is below average."
Phil
Phil
AGREED 100%i think Kari is HOT
clearly this is not a thread hijack because it is about mythbusters
How would a treadmill offset the thrust moving the aircraft forward? The aircraft isn't teathered....A jet engine generates thrust, but it doesnt move any air over the wings. Thus, no airspeed. A treadmill will NOT affect thrust, but it will offset the fact that the thrust would move the airplane forward, generating the lift required to make the airplane fly. If the jet engines could generate enough thrust to overcome gravity without the added help of lift, then the airplane would take off.
So take a small aircraft, and put really powerful engines on it (basically a rocket), it will work. Otherwise, it wont happen on any airplanes I know of.
It wouldn't.How would a treadmill offset the thrust moving the aircraft forward? The aircraft isn't teathered....
'zackly....It wouldn't.How would a treadmill offset the thrust moving the aircraft forward? The aircraft isn't teathered....
That is the assumption that is being made here that blows this whole myth apart.
Running a treadmill forward or backward under the plane would not effect the plane's speed through the air. Relative ground speed doesn't matter.
Put it this way, as you bring the engine thrust up and the plane begins to move forward, running the conveyor belt in the direction of travel at the same speed would result in the wheels not turning, but the plane would still be traveling at the same speed through the air. Like wise, running the conveyor backwards would result in the wheels spinning twice the "normal" speed, but the plane speed through the air would be the same..
Brilliant! This must assume that you've not just peed and you've got enough piss to fill the hole (which he should have stated was a water tight tube). The fork, wrench and the wire was a decoy, unless you consider that the pee is damaging to the tube.That's to easy, you piss in the hole untill the tennis ball floats to the top, no tools needed, well i guess some people call it there TOOL. Just gotta think outside the box. Stan...So, You are stuck in a room with no windows and no doors.
There is a hole in the floor about a foot deep and just barely wider than the diameter of a table tennis ball. There is a table tennis ball at the bottom of the hole.
You have a fork, a wrench, and a long, thin plastic wire.
How do you get the ball out of the hole without damaging anything?
I used to know this young lady that could, ah err, never mind. Stan.Brilliant! This must assume that you've not just peed and you've got enough piss to fill the hole (which he should have stated was a water tight tube). The fork, wrench and the wire was a decoy, unless you consider that the pee is damaging to the tube.That's to easy, you piss in the hole untill the tennis ball floats to the top, no tools needed, well i guess some people call it there TOOL. Just gotta think outside the box. Stan...So, You are stuck in a room with no windows and no doors.
There is a hole in the floor about a foot deep and just barely wider than the diameter of a table tennis ball. There is a table tennis ball at the bottom of the hole.
You have a fork, a wrench, and a long, thin plastic wire.
How do you get the ball out of the hole without damaging anything?
Another possibility (if there was a hole at the bottom of the tube to let air in) is to blow across the top of the tube (or hole as he called it). Bernoulli's principle would come into effect and pull the ball up the shaft of the tube. If you had enough breath, the ball would pop up above the hole and you grab it (or just blow it away). Again, the tools are a decoy.
Mitzy Dupris ........................... She could smoke a cigarette .................................... oops, same as you, never mind.I used to know this young lady that could, ah err, never mind. Stan.
I don’t know how FJRottie got himself into this situation (see this post) I’ve PMed him a solution, I’m guessing that he is out trying it right now. Hopefully he can get his balls back....So, You are stuck in a room with no windows and no doors. There is a hole...get the ball out of the hole...
That sounds a bit optimistic.This thread proves that old saying,"Half the population is below average."
Phil
Right, the assumtion in the original question is that the treadmill will offset any forward movement, which in reality it wont. The airplane will simply drive off the treadmill (if there is enough friction), or nose dive into the ground (in a near frictionless environment).So what do planes use to "fly" other than thrust produced by the engines? (which provides velocity to the airframe which causes the wings to create lift)I believe the theory is that if the treadmill is driven so that the wheel speed matches the airspeed at which the thrust would be driving the aircraft, the effective groundspeed would be zero and thus the aircraft would be relying solely on the thrust produced by the engine(s).
There qre some very powerful military aircraft that might be able to fly relying completely on the thrust produced by the engines, but....
How could a ski-plane take off on snow if an airplane needs wheels driving it?
ONLY if that thrust was vectored downward. In the case of the treadmill, the thrust is vectored horizontally. The whole purpose of the treadmill is to prevent forward movement of the plane through space. Thrust vs. weight ratio is only relevant if the plane is pointed upwards (or thrust downwards) to any degree. If the plane was pointed at 90 degrees to horizontal (ie, nose of plane straight up, thrust straight down) then if thrust equals mass of the plane, the plane would then weigh ZERO at that moment. Add one more pound of thrust and the plane will rise. If the plane is pointed at anything less than 90 degrees, Then by vector calculations, it would take much more thrust than the weight of the plane to make it rise. When thrust is horizontal to the pull of gravity, it can be infinite. The plane will not rise so long as the treadmill can keep up. When it can't keep up, the plane will move forward relative to the ground, airspeed will increase to the point where it will allow the wings to produce lift. Once the treadmill can no longer keep, the parameters of the experiment just changed.and in that case the only way it would take off is if the thrust vs. weight ratio were great enough.
Please explain how the treadmill will prevent forward movement of any plane.The whole purpose of the treadmill is to prevent forward movement of the plane through space.
Apparently some of you did.Did some of you guys fall asleep during physics class?
It wont, but the original question assumes it would stop forward movement (otherwise there would be no point to having the treadmill). In reality, it would drive off the treadmill, or nose dive into the ground.Please explain how the treadmill will prevent forward movement of any plane.The whole purpose of the treadmill is to prevent forward movement of the plane through space.
Apparently some of you did.Did some of you guys fall asleep during physics class?
As you apply thrust (either by propeller or by jet or rocket or fairy wings), the plane will begin to move forward. This forward movement is negated when you run the treadmill. The treadmill serves to keep the plane in the same position relative to the ground the treadmill is bolted to. The more thrust, the faster the treadmill runs. This is how the treadmill prevents the forward movement of the plane. The plane is NOT moving. The treadmill under it, is.Please explain how the treadmill will prevent forward movement of any plane.The whole purpose of the treadmill is to prevent forward movement of the plane through space.
Apparently some of you did.Did some of you guys fall asleep during physics class?
Wrong. You are using the example of the running man and it's a bad example. A running man develops forward thrust from pusjing off against the treadmills belt. A plane, whether Jet drive or Prop drive, develops forward thrust by pushing against the air. Actually in a Jet is the displacement of air, but that is the same thing for our purposes. Therefore a conveyor belt will not have any effect on the thrust or the forward movement of the plane.As you apply thrust (either by propeller or by jet or rocket or fairy wings), the plane will begin to move forward. This forward movement is negated when you run the treadmill. The treadmill serves to keep the plane in the same position relative to the ground the treadmill is bolted to. The more thrust, the faster the treadmill runs. This is how the treadmill prevents the forward movement of the plane. The plane is NOT moving. The treadmill under it, is.Please explain how the treadmill will prevent forward movement of any plane.The whole purpose of the treadmill is to prevent forward movement of the plane through space.
Apparently some of you did.Did some of you guys fall asleep during physics class?
Certainly, you've run on an excercise treadmill? How are you able to NOT run into the front part of the treadmill? Answer: The treadmill is operating. You can maintain your position even if you run faster by simply making the treadmill operate faster. Thus, the treadmill is preventing your forward movement. YOU, are not moving forward. The treadmill under you is moving backwards. You can run as fast as you like. As long as you keep the treadmill operating at the same rate as you're running, you will go NOWHERE.
Nope, I was wide awake during physics class and I paid attention. Besides, "vectoring" was a whole other parameter that was being introduced into this discussion - a parameter that wasn't intended in the airplane on a conveyer belt experiment. It was the topic of vectors that I was relating to physics and staying awake for.
So, when is this episode of Mythbusters? I checked the programming for Mythbusters and I didn't see an episode that dealt with this topic.
As you apply thrust (either by propeller or by jet or rocket or fairy wings), the plane will begin to move forward. This forward movement is negated when you run the treadmill. The treadmill serves to keep the plane in the same position relative to the ground the treadmill is bolted to. The more thrust, the faster the treadmill runs. This is how the treadmill prevents the forward movement of the plane. The plane is NOT moving. The treadmill under it, is.Please explain how the treadmill will prevent forward movement of any plane.The whole purpose of the treadmill is to prevent forward movement of the plane through space.
Apparently some of you did.Did some of you guys fall asleep during physics class?
Certainly, you've run on an excercise treadmill? How are you able to NOT run into the front part of the treadmill? Answer: The treadmill is operating. You can maintain your position even if you run faster by simply making the treadmill operate faster. Thus, the treadmill is preventing your forward movement. YOU, are not moving forward. The treadmill under you is moving backwards. You can run as fast as you like. As long as you keep the treadmill operating at the same rate as you're running, you will go NOWHERE.
Nope, I was wide awake during physics class and I paid attention. Besides, "vectoring" was a whole other parameter that was being introduced into this discussion - a parameter that wasn't intended in the airplane on a conveyer belt experiment. It was the topic of vectors that I was relating to physics and staying awake for.
So, when is this episode of Mythbusters? I checked the programming for Mythbusters and I didn't see an episode that dealt with this topic.
EXACTLY! Thank you!It wont, but the original question assumes it would stop forward movement (otherwise there would be no point to having the treadmill). In reality, it would drive off the treadmill, or nose dive into the ground.
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