Looking for an intelligent argument. (Terminal Velocity)

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TheEngineer

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Re: Looking for an intelligent argument.
« Reply #720 on: August 31, 2008, 08:23:57 AM »
EP will not work because that would only apply to what the person saw, the predictive power of a model is an entirely different matter.
The EP applies perfectly in this situation.  This is not a case of non locality, as tidal forces are unimportant. 


"I haven't been wrong since 1961, when I thought I made a mistake."
        -- Bob Hudson

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Dr Matrix

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Re: Looking for an intelligent argument.
« Reply #721 on: August 31, 2008, 10:08:15 AM »
Is the problem (still) being debated that there is some supposed discrepancy between the FE model and the RE model for someone jumping out of an aeroplane (for instance)? If it is then I will attempt to derive both cases side by side, in the interests of helping something get resolved - first I just need to be sure I understand the FE model in question - from the nature of the question I assume that the UA only applies to the Earth itself, and not to the air, aeroplane or skydiver?
Quote from: Arthur Schopenhauer
All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident.

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sokarul

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Re: Looking for an intelligent argument.
« Reply #722 on: August 31, 2008, 10:15:33 AM »
Ok... If this crap continues, I might have to lock this thread and declare FE as the winner. This dude (cbarnett97) just don't get it.

And another retarded claim in this thread that somehow FE wins.
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Parsifal

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Re: Looking for an intelligent argument.
« Reply #723 on: August 31, 2008, 10:26:04 AM »
Is the problem (still) being debated that there is some supposed discrepancy between the FE model and the RE model for someone jumping out of an aeroplane (for instance)? If it is then I will attempt to derive both cases side by side, in the interests of helping something get resolved - first I just need to be sure I understand the FE model in question - from the nature of the question I assume that the UA only applies to the Earth itself, and not to the air, aeroplane or skydiver?

That assumption is correct, yes. The acceleration is only indirectly applied to the air, aeroplane and skydiver through the electrostatic repulsion between atoms in the Earth and atoms in the air, and similarly between atoms in the air and atoms in airborne objects.
I'm going to side with the white supremacists.

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Dr Matrix

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Re: Looking for an intelligent argument.
« Reply #724 on: August 31, 2008, 10:49:23 AM »
(Request permission to post 1.5 A4 pages in .gif to demonstrate simple solution to this problem...)
Quote from: Arthur Schopenhauer
All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident.

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Parsifal

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Re: Looking for an intelligent argument.
« Reply #725 on: August 31, 2008, 10:52:22 AM »
(Request permission to post 1.5 A4 pages in .gif to demonstrate simple solution to this problem...)

Post away, sir. GIF files are very small, so there shouldn't be a problem.
I'm going to side with the white supremacists.

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Dr Matrix

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Re: Looking for an intelligent argument.
« Reply #726 on: August 31, 2008, 11:08:32 AM »
OK here goes, I apologise if this comes out massive...




Hopefully that's come out ok. Basically this aims to show that a skydiver cannot use terminal velocity to differentiate between the UA and gravitation in an FE model where the body under UA does not gravitate.

This last part is the biggest problem for me, but that doesn't mean that as a model the maths doesn't work out for this problem.
Quote from: Arthur Schopenhauer
All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident.

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Trekky0623

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Re: Looking for an intelligent argument.
« Reply #727 on: August 31, 2008, 11:11:01 AM »
What are we arguing about?

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Jack

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Re: Looking for an intelligent argument.
« Reply #728 on: August 31, 2008, 11:15:16 AM »
Terminal velocity of FE.

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TheEngineer

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Re: Looking for an intelligent argument.
« Reply #729 on: August 31, 2008, 11:15:42 AM »
So, basically, my derivation is correct.  And much less messy.


"I haven't been wrong since 1961, when I thought I made a mistake."
        -- Bob Hudson

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Dr Matrix

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Re: Looking for an intelligent argument.
« Reply #730 on: August 31, 2008, 11:21:27 AM »
Chill out Engy - if there was a way to stick TeX straight in here I'd just do that, but as far as I know (tell me otherwise, please!!) there isn't, so I went for the pen and scanner option. Sorry if it hurts your eyes.

Secondly, surely you can appreciate the argument on here wasn't going anywhere. Without external intervention it was never going to end - as entertaining as it is to check in occasionally I couldn't help but feel it had gone on long enough.

Thirdly, yes, my (intentionally simplistic) derivation shows that you are correct in that in a non-gravitating, UA-based, FE model will give the same terminal velocity as a gravitating RE model.  Don't bite the hand that feeds you.
Quote from: Arthur Schopenhauer
All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident.

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TheEngineer

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Re: Looking for an intelligent argument.
« Reply #731 on: August 31, 2008, 11:25:04 AM »
My reply contained no malice.


"I haven't been wrong since 1961, when I thought I made a mistake."
        -- Bob Hudson

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Trekky0623

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Re: Looking for an intelligent argument.
« Reply #732 on: August 31, 2008, 11:32:29 AM »
There's terminal velocity in FE.

As the air rushes past a person falling out of an airplane (air which is resting upon the FE and is therefore also being accelerated at 9.8 m/s2, the air resistance will eventually start to accelerate the person at a rate, and the person will continue to accelerate at that slower rate and fall at a constant velocity, aka terminal velocity.

FE wins.

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Dr Matrix

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Re: Looking for an intelligent argument.
« Reply #733 on: August 31, 2008, 11:34:26 AM »
Trekky, did you actually read my post? Or any of Engy's?

Engy - my bad, misread your first post as bitchy so decided to patronise you in response, just to show what a big man I am.
Quote from: Arthur Schopenhauer
All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident.

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Trekky0623

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Re: Looking for an intelligent argument.
« Reply #734 on: August 31, 2008, 11:36:07 AM »
I'm assuming you, Engy, and I are arguing the same thing, and cbarnett doesn't get it.

Correct?

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Dr Matrix

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Re: Looking for an intelligent argument. (And Terminal Velocity of FE)
« Reply #735 on: August 31, 2008, 11:38:40 AM »
Pretty much. C'est la vie.
Quote from: Arthur Schopenhauer
All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident.

*

TheEngineer

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Re: Looking for an intelligent argument. (Terminal Velocity)
« Reply #736 on: August 31, 2008, 11:46:49 AM »
Quite correct.  My derivation is a few pages back if you wish to take a look at it Trekky.


"I haven't been wrong since 1961, when I thought I made a mistake."
        -- Bob Hudson

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sokarul

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Re: Looking for an intelligent argument.
« Reply #737 on: August 31, 2008, 01:25:30 PM »
So, basically, my derivation is correct.  And much less messy.

You are an engineer and you think his scans are messy?  That's funny. 
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It's no slur if it's fact.

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TheEngineer

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Re: Looking for an intelligent argument.
« Reply #738 on: August 31, 2008, 02:40:55 PM »
You are an engineer and you think his scans are messy?  That's funny. 
I don't get it.


"I haven't been wrong since 1961, when I thought I made a mistake."
        -- Bob Hudson

Re: Looking for an intelligent argument. (Terminal Velocity)
« Reply #739 on: August 31, 2008, 03:20:53 PM »


Only 2 things are infinite the universe and human stupidity, but I am not sure about the former.

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TheEarthIsRoundForever

Re: Looking for an intelligent argument. (Terminal Velocity)
« Reply #740 on: August 31, 2008, 03:27:11 PM »
Um, I hope for your sake that this is a joke. But if not, let me let you in on something. Um, the earth is...ROUND!

(USER WAS BANNED FOR THIS POST)
« Last Edit: August 31, 2008, 03:29:19 PM by Hara Taiki »

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Trekky0623

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Re: Looking for an intelligent argument. (Terminal Velocity)
« Reply #741 on: August 31, 2008, 04:17:32 PM »
That doesn't change the fact that there will still be a terminal velocity in FE.

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Trekky0623

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Re: Looking for an intelligent argument. (Terminal Velocity)
« Reply #742 on: August 31, 2008, 04:19:12 PM »
RE Free Body Diagram

/\ - Air resistance
O
|
\/ - Gravitation


FE Free Body Diagram

/\ - Air resitance
O

/\ - UA
|___________ FE

Re: Looking for an intelligent argument. (Terminal Velocity)
« Reply #743 on: August 31, 2008, 05:27:09 PM »
That doesn't change the fact that there will still be a terminal velocity in FE.
yes but how it gets to its terminal velocity is different and that is a quantity that can be measured
Only 2 things are infinite the universe and human stupidity, but I am not sure about the former.

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Trekky0623

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Re: Looking for an intelligent argument. (Terminal Velocity)
« Reply #744 on: August 31, 2008, 06:13:25 PM »
How would you measure it?  Speed relative to Earth will be the same, and so will felt force.

Re: Looking for an intelligent argument. (Terminal Velocity)
« Reply #745 on: August 31, 2008, 06:58:19 PM »
How would you measure it?  Speed relative to Earth will be the same, and so will felt force.
no it will not, only the felt acceleleration relative to the air will felt to be zero
Only 2 things are infinite the universe and human stupidity, but I am not sure about the former.

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Trekky0623

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Re: Looking for an intelligent argument. (Terminal Velocity)
« Reply #746 on: August 31, 2008, 07:09:18 PM »
Same in RE and in FE.  At terminal velocity, acceleration is 0 relative to earth and air.  Your point?

Re: Looking for an intelligent argument. (Terminal Velocity)
« Reply #747 on: August 31, 2008, 07:13:41 PM »
Same in RE and in FE.  At terminal velocity, acceleration is 0 relative to earth and air.  Your point?
The rate of acceleration is different. Or are you arguing that since a formula 1 car can go 100kph and a Bmw 1series can go 100kph that they will get to that velocity at the same time?
Only 2 things are infinite the universe and human stupidity, but I am not sure about the former.

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Trekky0623

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Re: Looking for an intelligent argument. (Terminal Velocity)
« Reply #748 on: August 31, 2008, 09:31:04 PM »
It is the same.  Air is rushing past you at the same speed in RE and FE.  Air resistance will be the same, you will reach terminal velocity in the same amount of time as in RE.

RE

1. Jump out airplane.

2. Start to fall towards Earth at 9.8 m/s 2.

3. Air continues to accelerate past you, increasing air resistance.     

4. Air resistance causes person to accelerate at 0 m/s2.

5. You reach terminal velocity.
FE

1. Jump out airplane.

2. Earth moves toward you at 9.8 m/s 2.

3. Air continue to accelerate past you, increasing air resistance.

4. Air resistance causes person to accelerate at 0 m/s2.

5. You reach terminal velocity.

There is absolutely no difference.

Re: Looking for an intelligent argument. (Terminal Velocity)
« Reply #749 on: August 31, 2008, 09:36:56 PM »
It is the same.  Air is rushing past you at the same speed in RE and FE.  Air resistance will be the same, you will reach terminal velocity in the same amount of time as in RE.

RE

1. Jump out airplane.

2. Start to fall towards Earth at 9.8 m/s 2.

3. Air continues to accelerate past you, increasing air resistance.     

4. Air resistance causes person to accelerate at 0 m/s2.

5. You reach terminal velocity.[/color]
FE

1. Jump out airplane.

2. Earth moves toward you at 9.8 m/s 2.

3. Air continue to accelerate past you, increasing air resistance.

4. Air resistance causes person to accelerate at 0 m/s2.

5. You reach terminal velocity.[/color]
that is the mistake theengineer is making and everyone is following his lead, you can not relate it to the earth until you have reached your point of equalibrium.


if it is not in the box, then it can not be looked at until you finish resolving all the forces. the whole idea of doing a free body diagram is to look at the forces acting on the body. If I took an accelerometer up in a plane with me what would the accelerations be at the different times. The accelerometer knows nothing about the behavior of the earth, so how can it be taken into account when I am resolving all the forces
Only 2 things are infinite the universe and human stupidity, but I am not sure about the former.