So...about that plane on the treadmill...

"Darkwing" theducksmailATyahoo.com wrote in message
...
I am a regular on RAP, not a troll.

Then read the extensive thread that we already had on this subject before
you put your two cents in.

Show me video and I will believe it, if the plane is not moving relative
to the wind then the wing isn't making lift.

True.

I have ran on treadmills and I never felt a "wind" blowing in my face.

That's because you're using your feet for propulsion, and the treadmill was
negating your effort. There's no such effect for airplanes, as they don't
use their wheels for propulsion.

Your experience running on treadmills is irrelevant to the question at hand
(except for the intended effect of course, which is to confuse people like
you who haven't thought the whole thing through).

Pete

"Peter Duniho" wrote in message
...
"Darkwing" theducksmailATyahoo.com wrote in message
...
I am a regular on RAP, not a troll.

Then read the extensive thread that we already had on this subject before
you put your two cents in.

Show me video and I will believe it, if the plane is not moving relative
to the wind then the wing isn't making lift.

True.

I have ran on treadmills and I never felt a "wind" blowing in my face.

That's because you're using your feet for propulsion, and the treadmill
was negating your effort. There's no such effect for airplanes, as they
don't use their wheels for propulsion.

Your experience running on treadmills is irrelevant to the question at
hand (except for the intended effect of course, which is to confuse people
like you who haven't thought the whole thing through).

Pete


The plane IS hauling ass in relation to the moving treadmill BUT the wings
see zero lift due to the plane not moving relative to any air in the room. I
really think I am right the plane will not take off. The type of propulsion
is irrelevant. I guess we will have to agree to disagree until someone
actually does the experiement and video records it.

--------------------------------------
DW

The only way the treadmill can stop or slow the airplane is to create
more Drag than Thrust.

The reason the airplane will be able to accelerate is that the
treadmill does not create any significant drag aircraft.

When the treadmill hits 500MPH how much force will it take to hold the
airplane in position?

With perfect frictionless bearings it will take 0 force. If the engine
is generating any thrust the airplane will move forward no matter what
the treadmill does.

Brian.

"Brian" wrote in message
ups.com...

The only way the treadmill can stop or slow the airplane is to create
more Drag than Thrust.

The reason the airplane will be able to accelerate is that the
treadmill does not create any significant drag aircraft.

When the treadmill hits 500MPH how much force will it take to hold the
airplane in position?

With perfect frictionless bearings it will take 0 force. If the engine
is generating any thrust the airplane will move forward no matter what
the treadmill does.

Brian.


So lets say I know my little RC plane takes off at exactly 25mph. So I crank
up the treadmill to step up to 25mph so I can keep the RC plane up on the
treadmill, the plane is completely stationary in regards to anyone standing
next to the plane but when the treadmill hits 25mph and my little RC plane
is staying even with the treadmill you are telling me I can pull back on the
elevator stick and the plane will take off? I don't think so.

------------------------------------
DW

"Darkwing" theducksmail"AT"yahoo.com wrote in message
...
So lets say I know my little RC plane takes off at exactly 25mph. So I
crank up the treadmill to step up to 25mph so I can keep the RC plane up
on the treadmill, the plane is completely stationary in regards to anyone
standing next to the plane but when the treadmill hits 25mph and my little
RC plane is staying even with the treadmill you are telling me I can pull
back on the elevator stick and the plane will take off? I don't think so.

The scenario you suggest is impossible. The RC plane will accelerate
regardless of how fast the treadmill is running. Your "little RC plane"
will NOT be "staying even with the treadmill". It will take off, just as it
would from a normal runway surface.

And it doesn't take a video of such an attempt to prove it. All it takes is
a person who has a minimal education in physics and (key point here) is
willing to listen until they understand, and someone else willing to explain
it. You clearly fail to meet either the first or second criteria, or
possibly both, since we do have the third criteria met here in the
newsgroup.

You are disrespectful of the various posters here who have made an honest
effort to explain the situation to you and others. This is because you
refuse to bother to read the wealth of information on the topic that already
exists. Until you have done so, it would be a waste of time for anyone to
bother responding to any more of your assertions or questions. I know that
I won't.

Pete

"Peter Duniho" wrote in message
...
"Darkwing" theducksmail"AT"yahoo.com wrote in message
...
So lets say I know my little RC plane takes off at exactly 25mph. So I
crank up the treadmill to step up to 25mph so I can keep the RC plane up
on the treadmill, the plane is completely stationary in regards to anyone
standing next to the plane but when the treadmill hits 25mph and my
little RC plane is staying even with the treadmill you are telling me I
can pull back on the elevator stick and the plane will take off? I don't
think so.

The scenario you suggest is impossible. The RC plane will accelerate
regardless of how fast the treadmill is running. Your "little RC plane"
will NOT be "staying even with the treadmill". It will take off, just as
it would from a normal runway surface.

And it doesn't take a video of such an attempt to prove it. All it takes
is a person who has a minimal education in physics and (key point here) is
willing to listen until they understand, and someone else willing to
explain it. You clearly fail to meet either the first or second criteria,
or possibly both, since we do have the third criteria met here in the
newsgroup.

You are disrespectful of the various posters here who have made an honest
effort to explain the situation to you and others.

Man you are a dick. This has NOT been adequately explained or there would be
no question about it. If the plane is not moving on the treadmill but rather
keeping up with the speed that the treadmill is moving (yes planes DO have
throttle controls) the thing is going to takeoff with no air moving over the
wings? NO WAY.

This is because you refuse to bother to read the wealth of information on
the topic that already exists. Until you have done so, it would be a waste
of time for anyone to bother responding to any more of your assertions or
questions. I know that I won't.

Pete


Thank God for that, because you are a prick. Oh yeah, *PLONK*!

-------------------------------------------
DW

"Darkwing" theducksmail"AT"yahoo.com wrote in message
...


Man you are a dick. This has NOT been adequately explained or there would
be no question about it. If the plane is not moving on the treadmill but
rather keeping up with the speed that the treadmill is moving (yes planes
DO have throttle controls) the thing is going to takeoff with no air
moving over the wings? NO WAY.

Maybe, in your infinite wisdom, you can explain to me why the
treadmill is moving. Eh?

"Darkwing" theducksmail"AT"yahoo.com wrote in message


This has NOT been adequately explained or there
would be no question about it. If the plane is not moving on the
treadmill but rather keeping up with the speed that the treadmill is
moving (yes planes DO have throttle controls) the thing is going to
takeoff with no air moving over the wings? NO WAY.

Assuming you're a pilot, I don't understand why you think no air would be
moving over the wings, but I'll give this one good "college try"...

First, the question posed in the link by the OP of this thread is an
incorrect variation of the original. The original problem asks: "A plane is
standing on a giant treadmill. The plane moves in one direction, while the
treadmill moves in the opposite direction and at the same speed as the
plane. Can the plane take off?"

As has been explained, placing a car on the question's treadmill would
result in a stationary vehicle relative to the observer standing beside the
treadmill. The reason is the car derives its propulsion through the wheels
sitting on the treadmill and the speed of the car is measured by how fast
the wheels are turning. The faster the wheels turn, the "faster" the car
moves. However, this is only relative to the treadmill belt. To the observer
standing beside the treadmill, the car is motionless. If the driver placed
his hand out the window, he would feel no wind even though his "speed" as
indicated by the speedometer may be 100 miles per hour.

This is very similar to your example of running on the treadmill. You did
not feel a relative wind in your face because you were stationary relative
to the observer standing beside the treadmill. The reason you were
stationary is you generate your propulsion by moving your feet against the
ground (or belt, in this case) and the belt is moving in the opposite
direction and same speed of your "travel". Like the car, your speed is
measured by how fast your feet move from front to rear and they match the
speed of the belt to cancel out each other.

Now, replace the car and runner with an airplane. The airplane derives its
propulsion from its engine pushing air from front to back. None of this
energy is sent to the wheels to propel the airplane. The speed of the
airplane is measured by the flow of air past the airplane, not the turning
of its wheels. As the airplane's engine spools up to takeoff power, air is
forced from front to rear and the plane moves forward regardless how fast
its wheels are turning. The observer standing beside the treadmill would
notice the treadmill speed up, the airplane's wheels turn twice as fast as
normal, and the airplane move forward (not stationary).

Speed is relative and the key here is the means of propulsion. The
airplane's speed is measured by how fast the air is moving past it, not by
how fast its wheels are turning or how fast the ground is flashing by. None
of the airplane engine's energy is transmitted to the wheels to generate
speed. All of the airplane's propulsion is derived from moving air
(otherwise it would never stay in the air after takeoff). Since the
treadmill has very little effect on the air (and what little effect it does
have actually helps the airplane generate more lift), the airplane will
indeed takeoff in the same distance it normally would use without the
treadmill. However, the airplane wheels would be turning at twice their
normal speed at the time of takeoff.


Try this experiment:

Take a toy car and attach it to a string. Tie the other end of the string to
a small spring scale. Place the car on the treadmill belt and hold the scale
in front of the car while you turn on the treadmill. Observe nearly zero
(essentially 1G) force being exerted on the string/scale. Speed up the
treadmill (for simplicity, let's say you set it to a constant 10mph) and
you'll observe no significant difference in force exerted on the string (the
only additional force is the friction of the car's axles). Now gently pull
the string/scale forward. As long as you maintain a 1G force on the string,
the car will continue to accelerate.

Now, to the observer standing beside the treadmill, was the car stationary
or moving forward? It's speed was certainly not zero as the car most
definitely moved from rear to front of the belt. What was the speed of the
car relative to the "driver" sitting inside the toy? The wheels would be
turning faster than 10mph. If the "driver" were to put his hand out the
window, how fast would the air be moving? Much slower than his wheels would
say he's moving, but faster than the driver I mentioned at the beginning of
this post.

Replace the toy with the mythical airplane above, replace your arm with the
airplane's engine (and propeller, if appropriate), then replace the string
with the airplane engine mounts. You should now be able to visualize why the
airplane sitting on that giant treadmill would most definitely takeoff.

If not, I wish you good luck and safe flight. You'll need it.

--
John T
http://sage1solutions.com/blogs/TknoFlyer
Reduce spam. Use Sender Policy Framework: http://openspf.org
____________________

"Darkwing" theducksmail"AT"yahoo.com wrote in message
...

"Brian" wrote in message
ups.com...

The only way the treadmill can stop or slow the airplane is to create
more Drag than Thrust.

The reason the airplane will be able to accelerate is that the
treadmill does not create any significant drag aircraft.

When the treadmill hits 500MPH how much force will it take to hold the
airplane in position?

With perfect frictionless bearings it will take 0 force. If the engine
is generating any thrust the airplane will move forward no matter what
the treadmill does.

Brian.


So lets say I know my little RC plane takes off at exactly 25mph. So I
crank up the treadmill to step up to 25mph so I can keep the RC plane up
on the treadmill, the plane is completely stationary in regards to anyone
standing next to the plane but when the treadmill hits 25mph and my little
RC plane is staying even with the treadmill you are telling me I can pull
back on the elevator stick and the plane will take off? I don't think so.

------------------------------------
DW


If the plane will take off at 25mph and you are standing on the treadmill
holding the plane, when the treadmill reaches 25 mph the plane will fly if
you let go of the plane.

If the engine on the plane is set to the proper power it will continue to
fly right beside you.

"Gig 601XL Builder" wrDOTgiaconaATcox.net wrote in message
...

"Darkwing" theducksmail"AT"yahoo.com wrote in message
...

"Brian" wrote in message
ups.com...

The only way the treadmill can stop or slow the airplane is to create
more Drag than Thrust.

The reason the airplane will be able to accelerate is that the
treadmill does not create any significant drag aircraft.

When the treadmill hits 500MPH how much force will it take to hold the
airplane in position?

With perfect frictionless bearings it will take 0 force. If the engine
is generating any thrust the airplane will move forward no matter what
the treadmill does.

Brian.


So lets say I know my little RC plane takes off at exactly 25mph. So I
crank up the treadmill to step up to 25mph so I can keep the RC plane up
on the treadmill, the plane is completely stationary in regards to anyone
standing next to the plane but when the treadmill hits 25mph and my
little RC plane is staying even with the treadmill you are telling me I
can pull back on the elevator stick and the plane will take off? I don't
think so.

------------------------------------
DW


If the plane will take off at 25mph and you are standing on the treadmill
holding the plane, when the treadmill reaches 25 mph the plane will fly if
you let go of the plane.

If the engine on the plane is set to the proper power it will continue to
fly right beside you.


How is that possible if the wings are stationary? Are you saying the thing
will take off due to the pure power setting to keep up at 25mph (or
whatever), nothing to do with the wings?

---------------------------------
DW