13 Nov 06
Originally posted by aging blitzerThe problem mentions a plane and the belt. IT mentions motion.
What 2 steps?
Acceleration isn't mentioned. Oh no. The belt cannot change speed either then.
Wheels aren't mentioned. There goes your method determining the plane's speed.
A DIRECT 1 STEP relationship of speed. After all, the one is in contact with and is supported by the other.
Plane's speed CAN be measured by airspeed (both on the ground and in the air -agreed). But you're going a step further in your assertion.
If there is no acceleration, your plane cannot fly.
If there are no wheels, what is the point of contact?
13 Nov 06
Originally posted by sugiezdThe plane's speed is measured relative to a stationary observer and therefore also relative to the air (as the air is stationary relative to the ground and to an observer).
Define how you measure the planes speed - remember it must corrolate with the belt's speed.
13 Nov 06
Originally posted by XanthosNZWoah.
The plane's speed is measured relative to a stationary observer and therefore also relative to the air (as the air is stationary relative to the ground and to an observer).
Where does this observer come from?
The plane and belt are mentioned, the concept of speed obviosly relates one to the other.
13 Nov 06
Originally posted by sugiezdNo it doesn't. Standard protocol for a plane is to measure air speed. Why would you bother measuring wheel speed (which is the speed relative to the belt) as air speed is what enables you to take off and therefore is the speed of consequence.
Woah.
Where does this observer come from?
The plane and belt are mentioned, the concept of speed obviosly relates one to the other.
The observer isn't required at all it just a stationary landmark.
14 Nov 06
Originally posted by XanthosNZSo, you are now redefining the problem.
No it doesn't. Standard protocol for a plane is to measure air speed. Why would you bother measuring wheel speed (which is the speed relative to the belt) as air speed is what enables you to take off and therefore is the speed of consequence.
The observer isn't required at all it just a stationary landmark.
"A plane is standing on a runway that can move (some sort of treadmill). The plane moves in one direction, while the conveyer moves at the same speed but in the opposite direction. Can the plane take off?"
Becomes:
"A plane is standing on a runway that can move (some sort of treadmill). The plane moves relative to an observer (or stationary landmark) in one direction, while the conveyer moves at the indicated airspeed of the plane but in the opposite direction. Can the plane take off?"
The answer then becomes , yes.
What a shame it's a different problem.
14 Nov 06
If you have enough lift force at the wings, the plane lifts.
If you don't have enough lift force at the wings, the plane can't lift.
If the plane lifts or not doesn't depend of the question, only of the fact if there is enough lift force at the wings.
Why does people think this is a hard question?
Now, listen at the people who actually have flight certificate and experience of flying...
14 Nov 06
Originally posted by FabianFnasThank you Biggles.
If you have enough lift force at the wings, the plane lifts.
If you don't have enough lift force at the wings, the plane can't lift.
If the plane lifts or not doesn't depend of the question, only of the fact if there is enough lift force at the wings.
Why does people think this is a hard question?
Now, listen at the people who actually have flight certificate and experience of flying...
Do you have a master's in stating the bleeding obvious?
The point in question is the possibility or otherwise that the plane can move forward in absolute terms or only relative to the surface of the belt.
14 Nov 06
Originally posted by sugiezdIf it is so bleeding obvious, then why this interest of the question?
Thank you Biggles.
Do you have a master's in stating the bleeding obvious?
The point in question is the possibility or otherwise that the plane can move forward in absolute terms or only relative to the surface of the belt.
If you're not interested if the plane is lifting or not, then why not just discuss any object on wheels? Why is planes so interesting?
14 Nov 06
Originally posted by FabianFnasWell spotted.
If it is so bleeding obvious, then why this interest of the question?
If you're not interested if the plane is lifting or not, then why not just discuss any object on wheels? Why is planes so interesting?
The fact that it's a plane is irrelevant.
It is important to some, that the wheels are not powered. I think that this too is irrelevant.
Now that you're up to speed - will YOU manage to take off'
14 Nov 06
Originally posted by sugiezd"The fact that it's a plane is irrelevant."
Well spotted.
The fact that it's a plane is irrelevant.
It is important to some, that the wheels are not powered. I think that this too is irrelevant.
Now that you're up to speed - will YOU manage to take off'
Then, why is the title of this thread "Why the plane takes off in laymans (my) terms" when is has nothing to do with the plane and whether or not it will lift?
14 Nov 06
There are several theories for the principles of flight and none have been proven to be a correct and overiding explanation. Essentially it is possible for a plan to take off at a zero ground speed (or even moving backwards) so long as the oncoming wind generate sufficient lift over the wings of the plan. This of course assumes that the hurricane type winds haven't already picked up the plan and 'bowled it down the runway'. Aeroplanes always take off into wind and land into wind for this reason (the ground speed is lower).
14 Nov 06
Originally posted by FabianFnasI apologise.
Sorry, didn't mean to offend anyone...
Just can't understand why this is so interesting so it merits 15 pages of postings in the second thread with the same theme...
Would you mind reading back a few pages and then you'll see what this is all about.