I think they do some rounding off. The 7.5 number I mentioned earlier is an
approximation. I think people doing sensitive measurements use a different
chart.
"Stephen M. Henning" wrote in message
news
Here is another one:

1) A liter of water is one kilogram by definition.
2) One kilogram is 2.2 pounds.
3) A quart is 2 pounds.

4) Hence, a liter is 1.1 quarts.

Conversion charts say that a liter is 1.0566882607957349 quarts. Why
the difference?









The above includes many approximations. The real values are.

1) A liter of water is one kilogram by definition at 4C and 1 atmosphere
of pressure. But at 20C a liter of water is 0.9982 kilograms.
2) One kilogram is 2.2046 pounds.
3) A quart is 2 pounds approximately. Actually at 4C a quart of water
is 2.086 pounds. At 20C a quart of water is 2.082 pounds.

4) Hence, at 4C a liter is 1.0567 quarts and at 20C a liter is 1.0567
quarts. So the common measures we take for granted are about 5 % off.

On or about Thu, 18 Nov 2004 21:52:58 GMT, "Ann in Houston"
wrote something like:

I certainly wouldn't have bothered to figure out the neck and all. The real
question was whether or not 12 cubic inches could hold 7.5 gallons.

Only if 231 cubic inches can hold one gallon.
--
Crashj

"Ann in Houston" wrote in message
. com...

[Snip]
The whole point I was trying to make and clarify
for myself is that if you took seven and a half gallon jugs and poured
them
into a container, they would fill a "lot" of space, and that "box" that is
12 inches in each direction didn't seem, in my mind, to be big enough to
hold it all. Does this not resonate with anyone, here? I have had
several
people react in disbelief when they were present as I was working out the
volume of possible pond configurations, and they heard for the first time
how many gallons of water were in a cubic foot.


If I didn't know the conversions between 1 cubic foot and gallons, I bet I
would easily underestimate how many gallons are in 1 cubic foot. Most people
dont have the skills or mental aptitude to look at different shaped volumes
and estimate the the difference in volume. Not to mention, a cubic foot is
not a measurement that most people use on a regular basis, so you don't have
a good mental picture as to what it looks like.

[Snip]

If I knew where to get a water-tight box like that, I would try it, just
to
see. I don't want to go get a bunch of rice or sand. I have plenty of
water. I do appreciate your understanding that this is just a curiosity
issue on my part. I think crash thought I wasn't willing to use the
conversion factor because it was hard for me to picture in my head.

Fill a 1 gallon milk jug with m&m's, do that 5 times, and you'll have a
lifetime supply of m&ms and your answer Around the holidays you can get 3
pound bags of m&ms, they're probably about 1/4 cubic foot.

Can't resist: was each bag of peanuts shaped like a cubic foot? Still,
that's pretty interesting. I wonder what they did before we had foam
peanuts. Rice would be hard to clean out of a car.

The method depends on how important an accurate answer is. Before foam
peanuts, they could have used ping pong balls, tennis balls, baseballs. The
larger the ball, the less accurate your answer is. Shipping rooms buy foam
peanuts by the cubic yard all the time. How accurate the answer is depends
on the application.

Buy a yard of cloth from the fabric store, and the clerk will pull a pull
some cloth over a yard stick, and give you a few inches more. Measure the
clearance of the valves to an engine and you might be concerned with 1/100th
of an inch. Design a circuit on a computer chip, and you're concerned with
micrometer. Draw your company logo using individual atoms on a silicon
crystal using individual atoms and you're probably concerned with nanometers
or smaller.

Snooze

"Stephen M. Henning" wrote...
Here is another one:

1) A liter of water is one kilogram by definition.
2) One kilogram is 2.2 pounds.
3) A quart is 2 pounds.

4) Hence, a liter is 1.1 quarts.

Conversion charts say that a liter is 1.0566882607957349 quarts. Why
the difference?


Conversion from mass to force is not exact and depends on conditions.
The same holds true for volume and force (or volume and mass). Water
volume changes (slightly) when temperature changes. For most of us
two or three significant digits is good enough.

Derek Broughton wrote:
I treated it as an exact cylinder - if I wanted to figure out the difference
due to curvature, I'd actually have emptied the contents into a proper
measuring container, as otherwise I'd have to take into account the
curvature on the bottom, the tapering on the top, the size of the neck (at
least, the one I used had some water in the neck), and the thickness of the
plastic (which looks like it probably isn't even uniform). It's a lot
easier to make assumptions :-) (besides which, since I couldn't get an
exact measurement, it was all rough anyway). In fact, either our water
supplier is cheating us, or the jug is actually a little bigger than my
calculation, because it should really be about 1150 cu.in. for a 5 (US)
gallon container.

Assumptions make for easier math for sure, but with a little calculus and
angle measurements and the like you could calculate it precisely. I mean
if you wanted to take the time that is. No need for emptying and filling
or calibrated measurements of volume that way. Just a precise mathematical
description of your container and some number crunching. But for general
purposes particularly when it comes to fish, I agree, making assumptions
or rounding a bit usually is okay. Just don't make too big of assumptions
if dealing with something like medication.

As to the OP, if you are having trouble conceptualizing the cubic foot
holding 7.5g of water, look at a standard 5.5g and 10g aquarium. A 5.5g is
about 16" x 8" x 10" ~= 0.75 cubic feet. A 10g is 20" x 10" x 12" ~= 1.39
cubic feet. The reason the 5g water jug looks bigger than the 5.5g tank is
just dimensions. It's tall and narrow with a big dent for the handle (at
least with my water company), which gives the impression of being bigger
than a cubic foot. I seem to remember reading a study where humans thought
a tall, narrow item held more when compared to an equal volume sized
short, round item. I believe the study was related to overeating due to
underestimating the volume of what one was consuming, but not positive.

"Cichlidiot" wrote in message
...
Assumptions make for easier math for sure, but with a little calculus and
angle measurements and the like you could calculate it precisely. I mean
if you wanted to take the time that is. No need for emptying and filling
or calibrated measurements of volume that way. Just a precise mathematical
description of your container and some number crunching. But for general
purposes particularly when it comes to fish, I agree, making assumptions
or rounding a bit usually is okay. Just don't make too big of assumptions
if dealing with something like medication.

Sure you could use triple integrals to calculate the volume of an
irregularly shaped object, but the fact is those of us that took calculus
would probably have to crack open our text books to remember how, since it's
not a concept that is used frequently. Additionally according to the US
Census only 24.4% of America holds a bachelors or greater, and bear in mind
many degrees do not require exposure to higher levels of math.

Finally the original poster was not questioning the math or the conversion
ratios, but expressing difficulty in visualizing how a 5 gallon jug was less
than 1 cubic foot.

References:
http://factfinder.census.gov/servlet...SF3_U&-_sse=on

Snooze wrote:
Sure you could use triple integrals to calculate the volume of an
irregularly shaped object, but the fact is those of us that took calculus
would probably have to crack open our text books to remember how, since it's
not a concept that is used frequently. Additionally according to the US
Census only 24.4% of America holds a bachelors or greater, and bear in mind
many degrees do not require exposure to higher levels of math.

I'll admit that I am more mathematically inclined than most (after all, I
took calculus in high school, completed my AP test in 30 mins getting a 5
and took calculus 3/C for fun in college). However, there are computer
programs which aid those less mathematically inclined should they desire.
I was just pointing out that there are methods other than estimations or
pouring x volume amounts to calculate the exact volume. Calculations that
were probably behind the design of the 5g water bottle.

Finally the original poster was not questioning the math or the conversion
ratios, but expressing difficulty in visualizing how a 5 gallon jug was less
than 1 cubic foot.

I believe I covered that in the second paragraph of my reply, which you
did not quote, when I explained the perceptual bias people have when
estimating the volume of tall, narrow containers compared to shorter
containers of equal volume. Even though I know otherwise, when I put my 5g
water bottle next to my 5.5g tank, the bottle "looks" bigger. It's just a
perceptual bias, perhaps related to other optical illusions regarding
size. I suppose what one can draw from this is that when in doubt, carry a
ruler, heh.

"Cichlidiot" wrote in message
...
I'll admit that I am more mathematically inclined than most (after all, I
took calculus in high school, completed my AP test in 30 mins getting a 5
and took calculus 3/C for fun in college).

Wow! Bragging about high school AP scores, what do you think this is?
usenet? *sarcasm*

Snooze

Snooze wrote:

"Cichlidiot" wrote in message
...
I'll admit that I am more mathematically inclined than most (after all, I
took calculus in high school, completed my AP test in 30 mins getting a 5
and took calculus 3/C for fun in college).

Wow! Bragging about high school AP scores, what do you think this is?
usenet? *sarcasm*

It was merely a statement of fact intended to show I do recognize my math
skills are above average, particularly when it comes to calculus, not
bragging. To get a perfect score on the AP is not easy, but to do it in a
fraction of the allotted time means I take to calculus like our fish do to
water. No need to get sarcastic over it. I thought I had detected an edge
in your last reply, but this pretty much confirms it. Have I offended in
some manner or is this a general approach you take to those who are
comfortable with calculus? I suppose it's of little consequence as this
little corner of the thread is venturing far off course, but I do wish to
reassure that no malice, belittling or conceit was intended in my replies.
I know there are other scientifically and mathematically minded on the
group, so I pointed out that calculus could be used to determine the
volume of the container. A nice little mental exercise should anyone get
the urge to try it out.

Snooze wrote:

"Cichlidiot" wrote in message
...
I'll admit that I am more mathematically inclined than most (after all, I
took calculus in high school, completed my AP test in 30 mins getting a 5
and took calculus 3/C for fun in college).

Wow! Bragging about high school AP scores, what do you think this is?
usenet? *sarcasm*

It was merely a statement of fact intended to show I do recognize my math
skills are above average, particularly when it comes to calculus, not
bragging. To get a perfect score on the AP is not easy, but to do it in a
fraction of the allotted time means I take to calculus like our fish do to
water. No need to get sarcastic over it. I thought I had detected an edge
in your last reply, but this pretty much confirms it. Have I offended in
some manner or is this a general approach you take to those who are
comfortable with calculus? I suppose it's of little consequence as this
little corner of the thread is venturing far off course, but I do wish to
reassure that no malice, belittling or conceit was intended in my replies.
I know there are other scientifically and mathematically minded on the
group, so I pointed out that calculus could be used to determine the
volume of the container. A nice little mental exercise should anyone get
the urge to try it out.

You play the lottery, don't you? Crashj

Ann replied: I get too disappointed and its just too stupid.

The lottery isn't stupid. What do you buy with that dollar, really? Not
much of a chance to win, but the hope, and we all need hope. The stupid
part is to spend more than a $1 each time, you see, if you're a believer,
if God/nature/the-powers-that-be, want you to win, you only need one
ticket. ;o) Therein, is how I justify my $1/play. ~ jan



~Power to the Porg, Flow On!~


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"~ jan JJsPond.us" wrote in message
...
You play the lottery, don't you? Crashj

Ann replied: I get too disappointed and its just too stupid.

The lottery isn't stupid. What do you buy with that dollar, really? Not
much of a chance to win, but the hope, and we all need hope. The stupid
part is to spend more than a $1 each time, you see, if you're a believer,
if God/nature/the-powers-that-be, want you to win, you only need one
ticket. ;o) Therein, is how I justify my $1/play. ~ jan

I used to be very much pro-lottery, until I read this article on the
Fool.com. The stats are astounding,
http://www.fool.com/features/1998/sp980521lottery.htm.

BV.

Ann in Houston wrote:

I certainly wouldn't have bothered to figure out the neck and all. The real
question was whether or not 12 cubic inches could hold 7.5 gallons. I
appreciate you doing it the way you did.




231 cu in per gal, not 12

12"x12"x12"= 1728 cu in = 1 cubic foot = 7.5 gal capacity.







--
http://www.kencofish.com Ken Arnold,
401-781-9642 cell 401-225-0556
Importer/Exporter of Goldfish,Koi,rare Predators
Shipping to legal states/countries only!
Permalon liners, Oase & Supreme Pondmaster pumps


$9.95 internet access https://sub.copper.net/promo/5339894.asp

Please Note: No trees or animals were harmed in the
sending of this contaminant free message We do concede
that a signicant number of electrons may have been
inconvenienced

~ jan JJsPond.us wrote:

You play the lottery, don't you? Crashj

Ann replied: I get too disappointed and its just too stupid.


The lottery isn't stupid. What do you buy with that dollar, really? Not
much of a chance to win, but the hope, and we all need hope. The stupid
part is to spend more than a $1 each time, you see, if you're a believer,
if God/nature/the-powers-that-be, want you to win, you only need one
ticket. ;o) Therein, is how I justify my $1/play. ~ jan



~Power to the Porg, Flow On!~


Joe; God, I pray every week that you will let
me hit the lottery.

God; Joe, I can do anything! But you have
to buy the damm ticket first!!!!!!









--
http://www.kencofish.com Ken Arnold,
401-781-9642 cell 401-225-0556
Importer/Exporter of Goldfish,Koi,rare Predators
Shipping to legal states/countries only!
Permalon liners, Oase & Supreme Pondmaster pumps


$9.95 internet access https://sub.copper.net/promo/5339894.asp

Please Note: No trees or animals were harmed in the
sending of this contaminant free message We do concede
that a signicant number of electrons may have been
inconvenienced

"KenCo" wrote in message
...
snip

Joe; God, I pray every week that you will let
me hit the lottery.

God; Joe, I can do anything! But you have
to buy the damm ticket first!!!!!!


I tell my wife all of the time, "When we win lottery..." and she always
responds, "Are you going to start playing?"

LOL.

BV.