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For all you smart people.

Posted: Mon Jun 09, 2008 5:13 pm
by dinowuff
Can you tell me how much a body of water 30 feet by 90 feet - say 6 inches deep would weigh?

What would be the pounds per square inch?

Reason:

Big rain lately here in the Midwest.

Part of our roof (where I work) had that much water on it and the maintenance guys were off to tackle the problem.

*note* I am sure those that work in building maintenance are equally attacked daily by stupid users /*note*

So it happens that this area is on top of a main conference room used by executives. A big complaint with maintenance was filed as to making sure people quit jumping on the roof. The sound was no doubt people pushing the water off and unclogging drains, etc.

So I gets to thinking. I can find the building specs and the weight tolerance of the roof. Then if you guys can figure out how heavy the water was, well It'll be a big help to the maintenance guys.

Please show your work. (I'm slow and may need to go over it a few times)

Thanks

Posted: Mon Jun 09, 2008 5:23 pm
by Shippwreck
Ok...

30 feet = 9.144 metres
90 feet = 27.432 metres
6 inches = 0.1524 metres

therefore times them all together and you had 38.2277429 metres cubed of water.

That is 38,227.7429 litres of water which means you had 38,227.7429 kg of water up there which equals

84,277.7468 lbs

(all conversions performed using google... isn't it amazing!)

Posted: Mon Jun 09, 2008 5:31 pm
by Morganlefay
Arent you in a northern state Dino....

so wouldnt the builders take in account ice and snow in their specs???

How many inches of snow ice you have this past winter....I know we had more then 6 inches...closer to a foot.

MLF

Posted: Mon Jun 09, 2008 5:36 pm
by Shippwreck
or 501 me's!

Posted: Mon Jun 09, 2008 5:36 pm
by dinowuff
Morganlefay wrote:Arent you in a northern state Dino....

so wouldnt the builders take in account ice and snow in their specs???

How many inches of snow ice you have this past winter....I know we had more then 6 inches...closer to a foot.

MLF
Yea but building specs here are a wide range. Everyone always builds to the minimum.

Just got back ship and hadn't seen your post.

This is where I am going to start. Or was...

Water at its maximum density (3.98 centigrade) weighs 8.3389 pounds per gallon

Posted: Mon Jun 09, 2008 5:40 pm
by dinowuff
so its length times width times depth.

30 feet * 90 feet times 6 inches.

30*90*what?

Posted: Mon Jun 09, 2008 5:42 pm
by Shippwreck
The value of 1 litre of water weighs 1 kg is for water at 4 degrees centigrade... I have to convert to metres and kg as I can't work with those backwards measurements ;)

Posted: Mon Jun 09, 2008 5:48 pm
by dinowuff
Ahh I understand. Obviously I can't figure out the backwards measurement either.

Posted: Mon Jun 09, 2008 6:44 pm
by Egaladeist
90 x 60 x .5 = 2700 x 62.37 ( 1 cubic foot of water weighs 62.37 pounds ) = 168,399 cubic feet of water

not sure how Google arrived at 84,277.7468 lbs ?

EDIT: some have a cubic foot of water weighing up to 62.42 pounds

Posted: Mon Jun 09, 2008 8:30 pm
by outerlimit
Does canada use the metric system or whatever they call the one we use in the US?

Posted: Mon Jun 09, 2008 10:25 pm
by Egaladeist
Canada has been metric for awhile now...we used to be on the Imperial System up till the 80's

the 80's brought three things almost all at once

1. the landed constitution
2. the metric system
3. french as an official language along-side english

Posted: Mon Jun 09, 2008 11:30 pm
by THE Doctor
Shippwreck wrote:or 501 me's!
Ok that's 501 weedy rakes.. what about lumpy dried up old oak's like .....

Posted: Mon Jun 09, 2008 11:36 pm
by rapier57
Huh???

Well, dino, sounds like you've got a pretty good load on the roof. You'll be lucky to not spring a pretty good leak. If you have access to the building specs, you should have something that gives a load value for the roof. Flat roof??? Without decent drainage??? Not a great design in the northern states, eh?

Posted: Tue Jun 10, 2008 1:42 am
by Morganlefay
I dont get the 501 thing either......

:?

We have a flat roof where I work...with pretty good drainage..although they were up there checking on it oftenwith the amount of snow we got this past winter.

Lots of people had to clear ice from their roofs this past winter...

we had a massive rain fall about 3pm...and the roof is still draining :shock:


MLF

Posted: Tue Jun 10, 2008 2:16 am
by Talen
For practical purposes, consider 1 cubic foot of freshwater weighs 62 pounds. The rest is academic. (Salt water weighs 64ish...)