viper313
One Shot, One Kill
+53|6858|Minnesota
It's similar to trying to ride a bike on a treadmill.  While you would think the centrifical force of the wheels spinning would keep you upright, they don't.  It's extremly hard to stay upright.  I know, I've tried.
JG1567JG
Member
+110|6805|United States of America
I already said no on page 1 and I will explain why a little better.
If you have a plane/jet on the east end of a runway facing west.  The runway acts as a large treadmill running in the opposite direction that the plane is going to take off. the runway itself moves from west to east and can match the planes speed and thrust.  When the plane powers up the engines and the runway starts to move matching the planes speed, the plane would appear to sit still.  The engines thrust would only stop it from going backwards off the runway.

Plane -->------>------>------> 300mph (wheelspeed because the plane would have no airspeed)
Runway <----<------<-----<-- 300mph

The plane wouldn't create any lift since the runway would counteract any speed the plane was able to create.

Now if the plane slowed to 200mph(wheel speed) and the runway stayed at 300mph the plane would go off the back of the runway.

If the plane would speed up to say 400mph (wheel speed) and the runway stayed at 300mph then the plane would move forward at 100mph (air speed).  If the plane only needed 100mph to take off then it would.

Last edited by JG1567JG (2006-12-26 11:33:07)

King_County_Downy
shitfaced
+2,791|6814|Seattle

For the last time, ground speed has nothing to do with it. Speed over ground does. The plane would move forward, therefor it would take off.

https://www.uploadfile.info/uploads/84d9904f7e.jpg
Sober enough to know what I'm doing, drunk enough to really enjoy doing it
viper313
One Shot, One Kill
+53|6858|Minnesota
Quick!!!!  Someone Call Mythbusters!!!!!!!
viper313
One Shot, One Kill
+53|6858|Minnesota
Think of it this way....   If you put a plane on a treadmill without the engines on and turned the treadmill on, where would the plane go?  Off the end of the treadmill.   Now turn the engines on too compensate for the treadmill.  The plane stays in the same spot on the treadmill.  Now increase the speed of the engines to full power but this time the treadmill increases its speed at the same time at the same rate.  The plane stays in the same spot!!!!!!! so there is no lift.
King_County_Downy
shitfaced
+2,791|6814|Seattle

zomg. No. The engines are not connected to the wheels. If we were talking about a car, you'd be right.
Sober enough to know what I'm doing, drunk enough to really enjoy doing it
JG1567JG
Member
+110|6805|United States of America

viper313 wrote:

Think of it this way....   If you put a plane on a treadmill without the engines on and turned the treadmill on, where would the plane go?  Off the end of the treadmill.   Now turn the engines on too compensate for the treadmill.  The plane stays in the same spot on the treadmill.  Now increase the speed of the engines to full power but this time the treadmill increases its speed at the same time at the same rate.  The plane stays in the same spot!!!!!!! so there is no lift.
No need to call myth busters since your post and mine a couple above already solved it.
King_County_Downy
shitfaced
+2,791|6814|Seattle

You guys are retards
Sober enough to know what I'm doing, drunk enough to really enjoy doing it
viper313
One Shot, One Kill
+53|6858|Minnesota

King_County_Downy wrote:

zomg. No. The engines are not connected to the wheels. If we were talking about a car, you'd be right.
So your saying if you put a plane on a treadmill without the engines on and turned the treadmill on, the plane wouln't fall off the end of the treadmill!!!!

What are you smoking and where can i get some!
ZeRoLiFe
Member
+7|6649|Maryland
NO, there is no airflow , its just moving the wheels , final answer!!!!!!!!!!!!!
ATG
Banned
+5,233|6746|Global Command
Lol @ this topic.
Kung Jew
That one mod
+331|6962|Houston, TX
LMAO...  KCD vs forces of gravity.

I think KCD is arguing that the force that is moving the plane forward is due to the engines thrusting* burnt fuel outta the back of the plane.

NOT an engine connected to the wheels.

What the OP is saying is that in a scenario where the plane is affected by gravity, in zero wind, on a treadmill that matches the thrust and compensating the friction caused by wheels/ball bearings/whatever, the plane won't take off due to the lack of air moving across the wings, because the plane is virtually standing still.

whew...

Close?

KJ




* for all the stoners out there reading this silly thread....  uh huhh hhuhhh... I said thrusting uh huhh huhhh huhhhhhh*
JG1567JG
Member
+110|6805|United States of America

King_County_Downy wrote:

zomg. No. The engines are not connected to the wheels. If we were talking about a car, you'd be right.
The engines are connected to the wheels by the plane.  The engines don't power the wheels but that has nothing to do with it. 

Look at it this way.  The plane starts to power up the engines and and increases its thrust to move it to 100mph.  Now the plane is moving but the runway is not yet.  When the plane gets to 100mph the runway starts to move.  Now the plane will keep moving forward untill the runway gets to 100mph to match the planes speed.  Once the runway gets to 100mph the plane would appear to come to a stop on the runway and take away any lift it needed to take off.
King_County_Downy
shitfaced
+2,791|6814|Seattle

viper313 wrote:

King_County_Downy wrote:

zomg. No. The engines are not connected to the wheels. If we were talking about a car, you'd be right.
So your saying if you put a plane on a treadmill without the engines on and turned the treadmill on, the plane wouln't fall off the end of the treadmill!!!!

What are you smoking and where can i get some!
You are exactly correct, the plane would remain still as the treadmill and the wheels spun. There would not be enough friction to move the 50 ton plane backwards. The wheels would spin and spin. Maybe, eventually, it would start to move the plane but yeah...as soon as the engines turned on, the plane would push itself forward.

Have you ever heard of a float plane or a plane with skiis on it? Friction would be more of an issue if we were talking about those.
Sober enough to know what I'm doing, drunk enough to really enjoy doing it
Kung Jew
That one mod
+331|6962|Houston, TX
GAAAHHHH!!

/throws hands up and digs out old college bong
King_County_Downy
shitfaced
+2,791|6814|Seattle

Seriously, stop playing video games and go back to school. You need to learn common sense. You fellers are on a one-way path to religion qwith this type of thinking.
Sober enough to know what I'm doing, drunk enough to really enjoy doing it
arson
Member
+99|6853|New York
The wheels  spinning on the plane do  not contribute to creating any forward movement.  It can " spin its wheels" all day long its not going anywhere....
ATG
Banned
+5,233|6746|Global Command

Kung Jew wrote:

whew...

Close?

KJ




* for all the stoners out there reading this silly thread....  uh huhh hhuhhh... I said thrusting uh huhh huhhh huhhhhhh*
Nah, this is classic shit, I think it should be stickied.
viper313
One Shot, One Kill
+53|6858|Minnesota

Kung Jew wrote:

LMAO...  KCD vs forces of gravity.

What the OP is saying is that in a scenario where the plane is affected by gravity, in zero wind, on a treadmill that matches the thrust and compensating the friction caused by wheels/ball bearings/whatever, the plane won't take off due to the lack of air moving across the wings, because the plane is virtually standing still.

whew...

Close?

KJ




* for all the stoners out there reading this silly thread....  uh huhh hhuhhh... I said thrusting uh huhh huhhh huhhhhhh*
Exactly, the key is friction. everyone is assuming that there is no friction on the wheels when there is.  There is no such thing as a frictionless wheel. uh huhh hhuhhh

Last edited by viper313 (2006-12-26 11:28:51)

King_County_Downy
shitfaced
+2,791|6814|Seattle

https://www.uploadfile.info/uploads/a8f300f1d7.gif
Sober enough to know what I'm doing, drunk enough to really enjoy doing it
bobby177
Member
+129|6690|Texas.. getting out asap
I feel you


THE PLANE WILL TAKE OFF!
THE PLANE WILL TAKE OFF!
THE PLANE WILL TAKE OFF!
THE PLANE WILL TAKE OFF!
THE PLANE WILL TAKE OFF!
THE PLANE WILL TAKE OFF!
THE PLANE WILL TAKE OFF!
THE PLANE WILL TAKE OFF!
THE PLANE WILL TAKE OFF!
THE PLANE WILL TAKE OFF!
ATG
Banned
+5,233|6746|Global Command
What if the treadmill only turned in purportion to the thrust of the plane. Like if it just stayed stationary and only turned as fast as the planes wheels. Would not the thrust of the engines eventually render the plane in effect weightless? Allowing it to fly?

Man, I need to re-up.
viper313
One Shot, One Kill
+53|6858|Minnesota
What's the most posts posted in one day?  I think we might break the record.   And I said that if the planes engines were off the plane would fall off the back.
nonexistentusmc
Member
+26|6662|Queens, NYC
I just came from the gym, got on the treadmill and guess what, if there is no thrust from the engine, (considering that this "treadmill" is an actual runway) the jet does move backwards and will go to the end. Theres a subway station in NYC where theres one of those conveyor belt type walkways. Put on your rollerblades and act like a plane with your engines off and youll just go with the flow(whichever way the walkway is going). You need equilibrium in the middle. If you're going to give me theres no friction in the wheels bs or the no engine in the wheels bs then youre still going to be wrong. SOMETHING has to hold the object(in this case airplane) in place for the wheels to rotate. We should go ask Newton about this. And I'm sure he'll side with the "no, the plane is not going to take off, and the plane will move with the belt if the engine is off" answer.

This is a crazy thread.
JG1567JG
Member
+110|6805|United States of America

King_County_Downy wrote:

Have you ever heard of a float plane or a plane with skiis on it? Friction would be more of an issue if we were talking about those.
Ok if a float plane needed 50mph airspeed to take off and it was floating in a river moving 50mph.
If the plane wanted to take off upstream if would have to apply the thrust to equal 100mph to get the 50mph airspeed to take off.

Now if the river was flowing at 100mph and the planes max thrust could only propel it to 100 mph it could not take off upstream. Since max thrust on the plane would only keep it sitting in one spot.

Last edited by JG1567JG (2006-12-26 11:49:37)

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