hmmm.... physics question for you guys....

[GodOfRhythm]

Re: hmmm.... physics question for you guys....

Eventhough I hinted towards a steady point of ground or air, there is no certainty of that here, it might as well be measured from the amount of spin/speed of the weels!

[Bert]

Re: hmmm.... physics question for you guys....

No wind??? If a plane moves forward at 200 MPH relative to the ground, and there is no wind or only a slight wind relative to stationary objects, then there will be 200 MPH of wind flowing over the plane's wings.

[GodOfRhythm]

Re: hmmm.... physics question for you guys....

OK I HAVE THE DEFINITE ANSWER, I thought about this stuff way too long, ready to spew:

What we have here is a question designed to create malice, it is not scientific or objective at all, this is an example of SUBJECTIVE READING AND COMPREHENSION at its best (in fact I might end up doing a thesis for Sociology out of this thread!)

Everyone will have a different opinion and will use different parameters, which are all possible, given the question at hand!

Here we go:

If the conveyor belt reads the speed of the weels to match up and calculate how much counterforce it must exert, then the plane will NOT move at all, the conveyor belt can achieve whatever speed it wants (even infinite) to match the SAME SPEED at an IDEAL level, causing zero forward motion.

Second opinion:

The plane's speed is being measured relative to the ground, in order for the conveyor belt to move at 1mph the plane must also travel 1mph relative to a fixed stationary point. The conveyor's belt measuring of the speed of the plane is done by taking the amount of movement relative to the fixed point divided by the time needed to achieve this motion. With frictionless weels and the plane being thrusted against air, it would take off.

---------

Ironically one could dispute that in the first case the infinite speed of the belt would cause gigantic amounts of airflow causing the plane to be either lifted up stationary or blown back.

[Bert]

Re: hmmm.... physics question for you guys....

It seems many people who think the plane won't fly are misunderstanding the assumptions. The problem does not say anywhere that the conveyer belt "turns at a speed to counteract the forward motion of the plane". It merely says that it turns at a speed opposite of the plane's forward motion. This will not counteract the forward motion of the plane, since the engines, not the wheels, are generating the forward force.

Uncounteracted forward force = forward motion relative to the ground & air = lift = flight.

But I guess this has already been stated 100 or so times by now [img]/images/graemlins/laugh.gif[/img] It's been fun, but I'm done here. Someone else can take up the pro-flight cause for now!

[sworn_enemy]

Re: hmmm.... physics question for you guys....

Ok, think of it this way...
Lets use a small 2 seater plane as a simple example. Lets say the plane weighs 1000lbs. With the plane sitting on the runway I can walk up to it and physically push it. I don't need to exert 1000lbs of force to move it, I only have to overcome the frictional drag of the wheels. Just like pushing a car in neutral. Lets say it takes 100lbs of force to overcome the frictional drag and move the plane. This is a constant. As long as the weight of the plane does not change the frictional drag will not change.

Now lets say it takes 500lbs of thrust to make the plane move down the runway at 20mph. This is also a constant. As long as the weight of the plane does not change the amount of thrust needed to move it at 20mph will not change.

Now if you put the plane on the conveyer that is moving backward 20mph the plane will move backward 20mph. To make the plane stay stationary and not roll back you only need to apply the 100lbs of force to overcome the frictional drag as stated above. With the engines firing at 500lbs. of thrust you have the first 100lbs of force keeping the plane stationary and 400lbs. of thrust propelling it forward. 500-100 = 400.

The conveyer cannot make 400lbs. of thrust disappear. Once the frictional drag has been overcome the conveyer will have no effect on the planes forward momentum. The conveyer can be going 100mph and the plane will still move forward at the same rate without increasing forward thrust. As thrust is increased the plane will accelerate regardless of what the conveyer is doing.

[Endrik]

Re: hmmm.... physics question for you guys....

the plane will take off only when it takes off in reality.

[Flametop]

Re: hmmm.... physics question for you guys....

Jack Kirkpatrick: Shanna, they bought their tickets, they knew what they were getting into. I say, let 'em crash.

Reporter: What kind of plane is it?
Johnny: Oh, it's a big pretty white plane with a red stripes, curtains at the windows, wheels, and it just looks like a big Tylenol.


Rex Kramer: Striker, have you ever flown a multi-engine plane before?
Ted Striker: No, never.
Rex Kramer: Shit. It's a God damn waste of time. There's no way he can land this plane.

Steve McCroskey: Get me someone who won't crack under pressure.
Johnny: How about Mister Rogers?

[GodOfRhythm]

Re: hmmm.... physics question for you guys....

Yes, I read 'too much' into the question, so I'll write my thesis on myself! [img]/images/graemlins/laugh.gif[/img]

I spent the last half hour googling, I saw several forums who also had 20+ pages threads with very heated discussions, but this is the answer:

http://www.avweb.com/news/columns/191034-1.html

What Bert said in his last post is in fact true and was what I was trying to say with the Subjective Comprehension term.

The sober individuals prevail, I guess.

[Endrik]

Re: hmmm.... physics question for you guys....

thtat link has been posted many times here [img]/images/graemlins/tongue.gif[/img]

[SeventhSon]

Re: hmmm.... physics question for you guys....

[ QUOTE ]

Uh....geee... thanks for leaving me out there bucko!!! [img]/images/graemlins/poke.gif[/img] [img]/images/graemlins/laugh.gif[/img]

[/ QUOTE ]

You were the bastard that started all this!!! You already knew the answer!!! [img]/images/graemlins/poke.gif[/img] [img]/images/graemlins/eviltongue.gif[/img] [img]/images/graemlins/laugh.gif[/img] [img]/images/graemlins/laugh.gif[/img] [img]/images/graemlins/laugh.gif[/img]

[toejam]

Re: hmmm.... physics question for you guys....

[ QUOTE ]
Jack Kirkpatrick: Shanna, they bought their tickets, they knew what they were getting into. I say, let 'em crash.

Reporter: What kind of plane is it?
Johnny: Oh, it's a big pretty white plane with a red stripes, curtains at the windows, wheels, and it just looks like a big Tylenol.


Rex Kramer: Striker, have you ever flown a multi-engine plane before?
Ted Striker: No, never.
Rex Kramer: Shit. It's a God damn waste of time. There's no way he can land this plane.

Steve McCroskey: Get me someone who won't crack under pressure.
Johnny: How about Mister Rogers?

[/ QUOTE ]
Surely you can't be serious.

I am, and don't call me Shirley.

Joey, have you ever seen a grown man naked? [img]/images/graemlins/laugh.gif[/img] [img]/images/graemlins/laugh.gif[/img] [img]/images/graemlins/laugh.gif[/img]

[GodOfRhythm]

Re: hmmm.... physics question for you guys....

Then what the fuck is the problem, it's all down to how much one reads into the question! [img]/images/graemlins/laugh.gif[/img]

This thread has given us a lot more insight into the personalities of the people here than any true objective answer (which doesn't 'really' exist, given the vague nature of the question)

If we presume it matches ONLY to the speed of the plane vs ground or air, then yes it will take off.

However one could also defend reading more into the question (albeit a bit less 'sober' or 'empiristic')

[Cleveland Metal]

Re: hmmm.... physics question for you guys....

My Jackson guitar is blue... What color is your jackson guitar? Do you like my Jackson guitar? I think yours is
very nice. Blah blah blah....

Debate is cool. Just don't be mean...

[toejam]

Re: hmmm.... physics question for you guys....

[ QUOTE ]
My Jackson guitar is blue...

[/ QUOTE ]
Yes, but what shade of blue is it actually? That could affect many things in the grand scheme of the world. [img]/images/graemlins/laugh.gif[/img] [img]/images/graemlins/laugh.gif[/img]

[Cleveland Metal]

Re: hmmm.... physics question for you guys....

As long as it doesn't go flying off a conveyer belt, I don't care what color it is. Except maybe pink... That would be bad.