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Old 31st May 2016, 10:29 AM   #2818
DaveThomasNMSR
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Originally Posted by Oystein View Post
...
Hence my immediate guess was correct: ?? = XX xx/s2.
No need to waste time with Excel or Open Office or whatever.
If you know anything about physics, that is.
Oystein, you got it right! (I saw your value this morning before you redacted it.)

Thanks for the numerous confirmations, all!

Originally Posted by DaveThomasNMSR View Post
It wouldn't be a waste of time at all. You can PROVE you understand physics simply by using popular programs like Microsoft Excel (or Office Libre Calc, available for free) to compute the 1st and 2nd derivatives of the NIST equation posted by TFK.

I was able to do so - a little tricksy, but extremely doable. Here is my result for acceleration, sans the vertical values.



All you have to do to prove some physics competency is to reproduce this acceleration graph from NIST's equation. I'm giving you a big boost by showing you the shape of the acceleration curve (you can check your work against this).

What is the value of acceleration at the ??s?

If you are incompetent at physics, you won't supply an answer.
Originally Posted by FalseFlag View Post
No. At best, it means you can google online calculators.

Why don't you post a link to the website you used, and paste the exact equation you used. Post screenshots to show each step. Then, copy and paste a picture of the graph of the equation.
Originally Posted by FalseFlag View Post
Why won't you post your data?

Why won't you post your steps?

If you were so certain that you were correct, you would want to make sure as many people as possible could review your work and get the same results.

Well, at least that is how it should work, but you're a skeptic, and obfuscation is what you thrive on.
Originally Posted by DaveThomasNMSR View Post
Here's a hint, FalseFlag:

To answer the questions posed by tfk and me, you would have had to understand that velocity is the time rate of change of position, and that acceleration is the time rate of change of velocity.

It's now obvious to everyone that you do NOT understand “middle school physics”.

Game over, dude.
Originally Posted by tfk View Post
His answer is correct.
I did this same calculation, in a completely different manner, many years ago.

His graph is the same as mine.
Originally Posted by rwguinn View Post
Waiting for glue to cure, paint to dry
Used Mathcad, got this:
IMAGE http://www.internationalskeptics.com...c65e930517.jpg

Ain't it amazing--people use 4 different methods, all get the same answer.
Science and Mathematics: They actually work. every time.
Originally Posted by Dave Rogers View Post
You know what's really funny about this?

From the context, the units in use, and the details of the graph, it's possible to guess the answer; in fact, it's almost impossible to guess it wrong.

If you know anything about physics, that is.

Dave
Originally Posted by Oystein View Post
Seing three horizontal lines, I was immediately (within 3 seconds) confused, thinking "does the NIST really use "feet", aren't they generally on the SI train already?". Because three horizontal lines only make good sense if the scale is xx ft/m2. Took me about 15 seconds more till I scrolled up and saw a graph confirming they indeed use ft.

Hence my immediate guess was correct: ?? = XX xx/s2.
No need to waste time with Excel or Open Office or whatever.
If you know anything about physics, that is.
Originally Posted by pgimeno View Post
Well, here's how I got it done. I could have used analytical derivatives, but that NIST equation was a little hairy, so I used numerical derivatives.

You can see that velocity is the time rate of change of position (cell E6), and that acceleration is the time rate of change of velocity (cell F8)


I can say with confidence that FalseFlag's incompetence at physics is a proven, well-documented fact.

#FalseFlagCluelessAtPhysics
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