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(wait 10 years before posting an Answer) -- (Physics Puzzle) -- Two glasses of water with an ice-cube in each

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henh...@gmail.com

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May 22, 2022, 8:43:52 PM5/22/22
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pls wait 10 years before posting an Answer !

____________________________

Two glasses of water with an ice-cube in each.

All the conditions are the same in the two
(volume, mass, temperature ...)

--- except ... one of the glasses has very salty water.

Which ice-cube is going to melt faster ?

leflynn

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May 23, 2022, 10:47:18 AM5/23/22
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Please wait five years before answering the following questions:
I do not understand how two equal volumes of water one very salty and the other not salty can have the same mass.
Even if I just consider the water content, I do not see how the one with salt can have the same mass of water in the same volume as the one without (any?) salt. Can and will you explain?
Are the surface pressures identical and are they 1 atm? Are the systems are rest at 1G with the glasses oriented so as to keep the water inside? Are the two ice cubes of the same salinities as the two different waters or are they the same non-salty (pure water) consistency?
Are the ice cubes at a uniform temperature and is it greater than, equal to or less than 0C? How tall is the glass and how much of it is filled? How large is the ice cube relative to the glass? What is the temperature outside the glass and is it maintained? Or should we consider the ice/water systems in isolation?


Kerr-Mudd, John

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Aug 4, 2022, 6:44:58 AM8/4/22
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Sorry, but both have already melted, probably in the first month.

--
Bah, and indeed Humbug.

Eric Sosman

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Aug 4, 2022, 11:40:18 AM8/4/22
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On 5/22/2022 8:43 PM, henh...@gmail.com wrote:
> pls wait 10 years before posting an Answer !
>
> ____________________________
>
> Two glasses of water with an ice-cube in each.
>
> All the conditions are the same in the two
> (volume, mass, temperature ...)
>
> --- except ... one of the glasses has very salty water.

Just a nit-picky follow-up: One molecule of water weighs (about) 18u,
while one of salt weighs about 58.5u. So, if the solutions in the two
glasses have equal mass, it means that for every 4 skillionths of a mole
of NaCl added you must remove 13 skillionths of a mole of water. It
would seem an astonishing coincidence if the solutions' volumes were
to come out equal, at equal temperature.

Or to put it another way: Salt water is denser than pure water of the
same temperature, so if the volumes are equal the masses cannot be,
and vice versa.

(I have long forgotten nearly all the chemistry I once knew, but even
when I still knew it my knowledge wasn't enough to let me calculuate the
abundances of H2O, H+, HO-, NaCl, Na+, and Cl- in either solution, never
mind the more exotic combinations that might crop up fleetingly. And
even if I knew their amounts, I still wouldn't have known how to figure
the density. But "salt water is denser" has remained with me, even if a
facility with equilibrium reactions has not.)

--
eso...@comcast-dot-net.invalid
Look on my code, ye Hackers, and guffaw!

henh...@gmail.com

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Aug 8, 2022, 12:34:50 PM8/8/22
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> Look on my code, ye Hackers, and guffaw! <------ which recent movie does this remind me of ?

( hint: suspension of disbelief )




thanks.... when i first saw your nit-picky follow-up... the 1st thing that came to my mind was
the Snoopy-esque rebuttal that .... that's like saying...

[ Dropping 2 identical metal balls ] (on somewhere on Earth) question is invalid
because the gravity would be slightly different for the 2 balls.



__________________________

>>> You don’t need a PhD in altitude-ology to know that running long distances at a higher elevation is more challenging than doing so at sea level. And chances are, you also don’t need a masters degree in maps to know that the southwestern state of New Mexico is fairly mountainous.

This weekend’s USATF Indoor Championships are being held in Albuquerque, NM and at an elevation of 5,312 feet. Regardless of your highest level of educational attainment, go ahead and put two-and-two together: we can expect the distance races (the mile & two-mile) to be a tad slower. But by how much? And what about non-distance events? How will the altitude impact their results?

Well, fortunately for all of us, Citius Mag’s in-house stat-master, graph-maker and armchair-physicist, Dr. Scott Olberding knows a thing or two about track & field as well as conveying information in easy-to-digest chart form.



You’ll notice that distances below approximately 400 meters actually see improvements in their marks when altitude is introduced into the equation. You sea level-dwellers probably don’t realize it, but drag (or air resistance) constantly hampers your ability to be your best self. At higher altitudes, there is less drag (the product in the equation) due to lower air density (our variable).



https://en.wikipedia.org/wiki/Long_jump

-------- i thought (diff in) gravity was the big factor.... is [air density] a bigger factor ?
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