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Mar 23 2014 05:43pm
Quote (oanfp @ 23 Mar 2014 22:40)
CORRECTION again, the building speed is cubic, i'm an idiot. our topic at the moment is related rates but this problem is supposed to be a challenge that my professor gave us as a weekly assignment


since it's mathematics you are talking about (hope it is :unsure: ), the building speed given is constant and measured in volume per day
it helps a lot in mathematics to be precise so that you know what you are dealing with
'Azrad' in post#19 gave you a lot of the information you need to solve your problem
what you need first is get some other parameters right, as stated in post#3 you need the width (assuming that the base is square) and one other measure related to slope or height

This post was edited by brmv on Mar 23 2014 05:44pm
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Mar 23 2014 06:59pm


Now, let's be real for a minute: I probably made a mistake in there somewhere. So you should do every step yourself, and compare your results to mine. Let me know what you come up with as the solution.
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Mar 24 2014 07:02am
Nice layout Azrad, as always !

From my side, I got as final answer :

dh/dt = 350 . [ Z / (3.a.(X -350.t)) ] ^ (2/3)

where Z = final height, X = final volume.

Plugging in numeral values gave me : dh/dt ~ 0.01 m after 10 years ( 1 cm per day).

Notice that, according to google, Cheops' pyramid was actually raised at a rate of 800 tons / day (and probably 800 tons of stones ~ 350 m^3).
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Mar 24 2014 07:34am
Quote (feanur @ Mar 24 2014 06:02am)
From my side, I got as final answer :

Plugging in numeral values gave me : dh/dt ~ 0.01 m after 10 years ( 1 cm per day).
Yeah that is consistent with what I got (about 1cm a day at that point in its construction). Heh on a side note I recently did an estimate to see how much mass each worker would have to be responsible for a day (which is just an average, I'm sure most of the workers never even moved stone, and were there for logistics). It was shocking low, about 26 kilograms a day. What is incredible is just the size of the operation.
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Mar 24 2014 10:04am
Quote (feanur @ 24 Mar 2014 13:02)
Nice layout Azrad, as always ! ...


he does that, doesn't he

Quote (Azrad @ 24 Mar 2014 13:34)
... It was shocking low, about 26 kilograms a day. What is incredible is just the size of the operation.


you actually have to nearly double that, because on a note on social history of egypt during those times
workers barely worked more than half the days, there were so many (religious) holidays in ancient egypt
also don't forget the substantial help from aliens :banana:
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Mar 25 2014 01:53am
Azard is on of my favourite people on jsp just because he never ceases to amaze me with his intelligence. It's always a good conversation when I get to pick his brain!
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Mar 25 2014 02:07am
Quote (NinjaSushi2 @ Mar 25 2014 12:53am)
Azard is on of my favourite people on jsp just because he never ceases to amaze me with his intelligence. It's always a good conversation when I get to pick his brain!


:blush:

well it's not intelligence sadly. my secret is that I'm an old geezer and I've just been around the block a few more times than you young whipper-snappers.
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