if you factor in some sort of resistance for friction, and you have some sort of infinitely fast conveyor belt, you could have enough resistance to hold it back. In real life, friction exists.
[quote=“boardjnky4,post:421,topic:37377"”]
if you factor in some sort of resistance for friction, and you have some sort of infinitely fast conveyor belt, you could have enough resistance to hold it back
[/quote]
True, but it was just a point I was trying to make. The speed the treadmill will be going will never build enough resistance to slow the plane from a forward speed.
[quote=“matter,post:419,topic:37377"”]
so… if the plane is not “moving” how does it take off with no air running under and over the wings?
no lift off…
[/quote]
[quote=“SubaruDan,post:416,topic:37377"”]
Picture this in your head:
I’m standing on a treadmill with rollerblades on, and I’m holding a leaf blower to represent a jet engine.
I turn the leaf blower on low, representing me taxiing to the runway, and as I start to move, the treadmill turns on, keeping me in the same location on the treadmill, so I’m not rolling off the front of it.
Then I turn the leaf blower to full power and it gives me some more thrust to get up to takeoff speed, so I get going really fast now, but the treadmill speeds up, and keeps me in the same spot.
So now I’m representing a jet engine providing maximum thrust to move me forward.
Quick, someone glue some wings to my sides.
OMG I didn’t start flying…
But wait… I found a piece of string in front of me, tied to the edge of the earth, I bet if I pull on it… YES!! I can move forward…
[/quote]
both of you just end yourself now
At we know who the morons are
01AudiS4, boardjnky4, dmoffitt, Fry, ILCisDEAD, itsJim, Jon, jrod0187, L8APEX1, matter, Motocrossx23, newman, rdandy5875, SilverGT, speedracer329, SubaruDan, zwarbyt, Karu
if you voted that way as a joke you count
derr, if a plane is at take-off speed, and the conveyer is moving at the same speed. The plane would not be moving. No moving = no air = no lift = you suck
they better get this right so I can laugh when it doesnt take off.
[quote=“66impalass,post:423,topic:37377"”]
both of you just end yourself now
At we know who the morons are
01AudiS4, boardjnky4, dmoffitt, Fry, ILCisDEAD, itsJim, Jon, jrod0187, L8APEX1, matter, Motocrossx23, newman, rdandy5875, SilverGT, speedracer329, SubaruDan, zwarbyt, Karu
if you voted that way as a joke you count
[/quote]
Clearly a few of us voted this way as a joke.
[quote=“matter,post:424,topic:37377"”]
derr, if a plane is at take-off speed, and the conveyer is moving at the same speed. The plane would not be moving.
[/quote]
Why isn’t the plane moving?
Time for flip mode.
I think I might be wrong, but I’m not sure why.
For all of you who doubt that the plane takes off, I challenge you to convince me. Please explain to me how this works.
This is my understanding:
Think of it in terms of a model plane on a tradmill.
if the plane is standing still, and the treadmill is moving, the plane will not move, the wheels will just spin (ideally). If you take your hand, and exert a foreward force on the plane, it will roll foreward.
This is exactly the same as the engines on a plane pushing the plane foreward. The movement of the treadmill is completely independent of the thrust of the engines.
If it was a car, it wouldnt move…
[quote=“Fry,post:427,topic:37377"”]
Time for flip mode.
I think I might be wrong, but I’m not sure why.
For all of you who doubt that the plane takes off, I challenge you to convince me. Please explain to me how this works.
[/quote]
simply friction.
if wheel speed = conveyor belt speed, plane can never take off.
if u stand on a treadmill on a skateboard, you have to hold onto something in order to not get dragged backwards, and holding urself forward is the force of the jet engine. when u turn up the speed of the treadmill, it takes more force to hold urself forward, so think about that in reverse. if the plane pushes forward and instantly the treadmill pulls in the reverse direction with enough force to keep the wheel speed equal to its(the belt) speed, the plane aint goin nowhere. simple as that. The way the question is worded, the plane aint goin nowhere.
[quote=“boardjnky4,post:429,topic:37377"”]
simply friction.
if wheel speed = conveyor belt speed, plane can never take off.
if u stand on a treadmill on a skateboard, you have to hold onto something in order to not get dragged backwards, and holding urself forward is the force of the jet engine. when u turn up the speed of the treadmill, it takes more force to hold urself forward, so think about that in reverse. if the plane pushes forward and instantly the treadmill pulls in the reverse direction with enough force to keep the wheel speed equal to its(the belt) speed, the plane aint goin nowhere. simple as that. The way the question is worded, the plane aint goin nowhere.
[/quote]
OK, I think I understand. I’m going to try to paraphrase that. Tell me if I’m correctly restating your thought.
“The wheels are not spinning freely. There is friction at the wheel bearings. So if the treadmill is spinning backwards really fast, the friction at the bearings will apply a force on the plane opposite the direction that the plane is trying to move. This will keep the plane from moving forward.”
Are we saying the same thing?
yes. there should also be a co-efficient of friction between the rubber on the wheels and on the treadmill
OK. Cool.
Lets suppose that we have some super duper uber high tech teflon on teflon wheel bearings greased with mighty taco. Does that change things?
HELLO
MY NAME IS
idunno man, your the engineer, you tell me
are you people really still debating this?
planes are not propelled through their wheels. seaplanes? ski-planes?
morons.
:picard:
OMG WHEEL FRICTION.
Unless the treadmill is moving at mach 39028478 to make enough friction to counter act the thrust of the planes motor the fucking plane is taking off.
I don’t even think it would be possible to have a bearing create enough friction to counter act thrust.
[quote=“66impalass,post:423,topic:37377"”]
both of you just end yourself now
At we know who the morons are
01AudiS4, boardjnky4, dmoffitt, Fry, ILCisDEAD, itsJim, Jon, jrod0187, L8APEX1, matter, Motocrossx23, newman, rdandy5875, SilverGT, speedracer329, SubaruDan, zwarbyt, Karu
if you voted that way as a joke you count
[/quote]
people like you need to end yourself…this is a forum where we brainstorm i suppose there is no need for name calling like we are in grammar school…
You might be the smartest person on the board and i might be the moron but im just trying to see what is wrong with the situation and just what i know. im not aerospace engineer or anything close to that for that matter. im a common person with a “how could this plane take off?” answer. so there is no need for you to go and call who ever thinks differently from you.
anyways…
so just think about this…
When you running on the treadmill in place do you feel any air?
Do you feel air when youre running off a treadmill?
im “ASKING” how fast is a airplane usually moving before it takes off?
at this certian speed doesnt the plane have air resistance for it to take off? the propeller/ jet engine like someone said only propell the airplane…this forward motion, not the propeller it self but the air resistance that it needs to lift the plane…
so if you understand it might be clear to you a little what im trying to get at…
so if the plane is on the treadmill with the jets/propeller at full speed…it doesnt have the air resistance it needs to lift off because there is no air resistance; the plane is not creating any air resistance.
the plane has to be in physically motion not just on a conveyor belt.
the physical motion means that its has air under its wings.
the only way it will fly is this
if you have the plane on a conveyor in a wind tunnel that replicates the wind speed it needs to take off at it will definitly fly.
this is what i also found…
go there and look at the demo of the hovercraft taking off…
u see how it needs the air flowing under the wings to lift it self…so imagine this…tie that hover craft to a pole…you think taht shit will still lift off?
that exactly what you are doing with the plane on a conveyor belt…the plane is in a fixed place.
Impalass66 explain to me how it will take off? because i wanna see it from your point so i can understand
[quote=“Avatar,post:68,topic:37377"”]
YO, Kohlrausch’s law says that the plane will crash and burn. Look it up homey. For real though, unless you have a really long treadmill the forward thrust will just nosedive the plane off the edge of the treadmill. The plane won’t just stand there. That would be like a plane being able to land on a treadmill as long as the surface was matched to the airspeed of the plane.
[/quote]
you are wrong! here is a demonstration of Reverse thrust, the plane can back up on its own
[quote=“Minglor,post:436,topic:37377"”]
OMG WHEEL FRICTION.
Unless the treadmill is moving at mach 39028478 to make enough friction to counter act the thrust of the planes motor the fucking plane is taking off.
I don’t even think it would be possible to have a bearing create enough friction to counter act thrust.
[/quote]
if the treadmill is equaling the speed of the wheels, then it would be.
think about it in small scale, your on a skateboard on a treamill, the treadmill speed = wheel speed, so you are standing still, and if i pull myself forward, then that means that the wheels are spinning faster then the conveyor is moving, this is what is needed for the plane to take off. the wheels NEED to spin faster then the treadmill, period. If the treadmill and wheels are going the same speed, as a person is holding onto the handle on the treadmill, then the plane isnt moving.
The question inadvertently states that the plane is not moving forward by saying that wheel speed is equal to conveyor belt speed. Its a trick physics question
[quote=“boardjnky4,post:439,topic:37377"”]
if the treadmill is equaling the speed of the wheels, then it would be.
think about it in small scale, your on a skateboard on a treamill, the treadmill speed = wheel speed, so you are standing still, and if i pull myself forward, then that means that the wheels are spinning faster then the conveyor is moving, this is what is needed for the plane to take off. the wheels NEED to spin faster then the treadmill, period. If the treadmill and wheels are going the same speed, as a person is holding onto the handle on the treadmill, then the plane isnt moving.
The question inadvertently states that the plane is not moving forward by saying that wheel speed is equal to conveyor belt speed. Its a trick physics question
[/quote]
you are correct but the mythbuster states that it will be going at the same speed at the plane. the plane is going no faster also…
so if in theory why the fuck would u put it on a convey to work harder then it needs too…
its like you are on gladiator…running up the conveyor belt to the top of the hill…which makes you work harder then u have too. when u can step to the side and get up the hill without working harder. lol
so the conveyor for the plane whill need to be the same distance as a runaway…so its pointless…
now if you put the hovercraft on that it will fly no problem lol. because the convey doesnt act on the craft that much.
do you know what i mean?