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Author Topic: What Happens To The Energy If I Dissolve A Compressed Spring ?  (Read 6855 times)

Offline neilep

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Dear Springologists,


"Winter Spring Summer or Fall" sang James Taylor and Carole King in 1971...If they had known that after collaborating on such a fine choon that a sheepy would ask a spring orientated question many years later..I wonder if they would have pursued that fine folky endeavour  ?!..........*le sigh*....One of the universes many mysteries I am sure ewe'll agree !!


As a sheepy I of course luff springs !..Springs are my all time favourite things that are made form coiled metal that bounce a lot and go squeek squeek when I jump on the bed !

looks here's some !!



Springs In Summer Earlier Today









Which ones' your fave ! ?..Oh my !!..I luff them all !!

If ewe push a spring together...it has some stored energy in it !..ewe can release this energy by letting go of the spring and it then goes ' boing'....which is nice !

Say I coiled a spring and then fastened it so that it could not release it's energy....and then place it in a container, restraining it further !....then....through a hole added some acid or stuff that would dissolve the spring....where would all the energy that is kept in the spring go to when it gets dissolved ?


Ewe see, i really do not know.....It's Friday...about 10pm and I wanna know !!.....I so wanna know that so much that I am going to hold my breath until ewe tell me !!

so..whajafink ?


hugs & shmishes



mwah mwah mwwah !!


Neil
If I Walk On My Bed
There's A Spring In My Step
xxxxxxxxxxxxxxxxxxxxxxxxxxx








« Last Edit: 24/07/2009 22:51:11 by neilep »


 

Offline Karen W.

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Thats a good question.....I wwould think as the acid breaks down the spring tension would slowly be released as thespring disolved into the jar but I would suspect that the volume inside the jar may change and instead of spring pressure you may end up with air pressure in its place..so maybe when you opened the jar you may either have a pop or because of the acidic reaction you may have a gaseous situation where either the smoke from the metals breakdown in the acid may actually cause pressure maybe....?My brain is not to scientific.. am I even close...?
 

Offline RD

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The energy stored in the spring would be converted into movement and cause permanent* deformation of the spring,
 when corrosion caused the spring to thin, weaken , buckle and eventually fracture.

[*permanent plastic deformation rather than reversible elastic deformation]
« Last Edit: 24/07/2009 23:40:28 by RD »
 

lyner

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I would picture the dissolved surface molecules of the spring moving off at speed as they became detached from their neighbours and the strain energy was transferred to Kinetic. The temperature of the acid would be increased as a result (in addition to that caused, possibly, by the chemical reaction)
 

Offline Edster

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To expand on Rd`s entry, and recalling a REME instructors knowledge dump,  springs can only be made of a certain range of steels, and the "springiness" is achieved by hardening and surface tempering. A blue oxide depth temper is usual, before polishing.

The material has a different structure on the outside to the inside, if the enclosing tempered sleeve is eroded, then it seems likely it will fracture, and the energy will be transferred to internal heating of the metal by the movement as the spring cracks  and any reaction to the liquid environment you suggest. It will mechanically react before it is dissolved.

This has raised an intriguing secondary question, small springs, are they the same grain structure throughout, or is the annealing process cut short to leave a hardened centre? They are easier to permanently deform, but that may just be scaling.

Any ideas?
 

Offline neilep

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Thats a good question.....I wwould think as the acid breaks down the spring tension would slowly be released as thespring disolved into the jar but I would suspect that the volume inside the jar may change and instead of spring pressure you may end up with air pressure in its place..so maybe when you opened the jar you may either have a pop or because of the acidic reaction you may have a gaseous situation where either the smoke from the metals breakdown in the acid may actually cause pressure maybe....?My brain is not to scientific.. am I even close...?


I ain't got a clue Mam !!..i think I'll ask the question ! ;)......however, it's interesting to see how ewe have thought this through !..I can see there are other answers so..lets go compare eh ?
 

Offline neilep

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The energy stored in the spring would be converted into movement and cause permanent* deformation of the spring,
 when corrosion caused the spring to thin, weaken , buckle and eventually fracture.

[*permanent plastic deformation rather than reversible elastic deformation]

Thanks RD...but the deformation will not be permanent...soon the spring will be all gone. In what way will the ' movement ' manifest ?
 

Offline neilep

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I would picture the dissolved surface molecules of the spring moving off at speed as they became detached from their neighbours and the strain energy was transferred to Kinetic. The temperature of the acid would be increased as a result (in addition to that caused, possibly, by the chemical reaction)

Thanks sophiecentaur. So the energy will transfer as heat. Fascinating. I wonder if there is way to have a spring naturally decompose quickly in water to produce hot water ?....

It's OK..it just dawned on me that maybe the energy involved in coiling the spring in the first place would be more than the energy released !..perhaps ?
 

Offline techmind

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I vote for sophiecentaur's answer.  ;)

That said, if energy is apparently "disappearing" anywhere, it's a pretty safe bet that it'll emerge as heat ;D


I do like your question though, neilep. Whatever made you think of that?
 

Offline RD

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Thanks RD...but the deformation will not be permanent...soon the spring will be all gone.

Before the spring has been dissolved it will have been deformed plastically rather than elastically. When a spring is compressed it is deformed (it gets shorter) but this deformation is elastic: it returns its original length when the compression force is removed.
However when something undergoes plastic deformation the change is "permanent" in that it doesn't bounce back.

In what way will the ' movement ' manifest ?
The spring will buckle, and may even fracture catastrophically, (with a bang).
 

Offline neilep

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What Happens To The Energy If I Dissolve A Compressed Spring ?
« Reply #10 on: 25/07/2009 13:34:45 »
I vote for sophiecentaur's answer.  ;)

That said, if energy is apparently "disappearing" anywhere, it's a pretty safe bet that it'll emerge as heat ;D


I do like your question though, neilep. Whatever made you think of that?

Thanks techmind.

It's funny what inspires ewe during play !..I was demonstrating to my 3 year old boy how strong i was by compressing a really big spring ! (*erhmm..it was stretched slinky*)...and then it just came to me while I was pretending to be all big and strong that if it weer a real spring and was not allowed to decompress properly then what would happen to the energy if if just deteriorated somehow !.....eh voila !!...le kwestion !!!
 

Offline Don_1

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What Happens To The Energy If I Dissolve A Compressed Spring ?
« Reply #11 on: 25/07/2009 16:59:07 »
If you were to leave your springy spring in water until it rusts away to nothing, then I suppose you would end up with spring water. Or have I miss understood (lovely young lady!) something? Am I missing something here, like a few brain cells, for example....
 

Offline neilep

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What Happens To The Energy If I Dissolve A Compressed Spring ?
« Reply #12 on: 25/07/2009 18:49:32 »
If you were to leave your springy spring in water until it rusts away to nothing, then I suppose you would end up with spring water. Or have I miss understood (lovely young lady!) something? Am I missing something here, like a few brain cells, for example....

no..no..I think ewe have it just right !!......If I come across some brain cells..we can share them !!..YAYYY !!.........I go look !!
 

Offline lightarrow

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What Happens To The Energy If I Dissolve A Compressed Spring ?
« Reply #13 on: 26/07/2009 22:30:11 »
I vote for sophiecentaur's answer.  ;)

That said, if energy is apparently "disappearing" anywhere, it's a pretty safe bet that it'll emerge as heat ;D
The same question was asked in an italian forum a couple of years ago.
When I gave that answer, someone (much more aknowledged than me) criticized it a little: "it's incorrect to say that the sping's potential energy is transformed in heat, because heat is just a flux of energy between two bodies, because of a temperature difference only. It' correct to say, instead, that the spring's potential energy was transformed into the acid's internal energy (with or without a temperature increase, the last possibility if there is a phase transformation)".

Anyway, the essence of the answer is right ;).
« Last Edit: 26/07/2009 22:32:59 by lightarrow »
 

Offline lightarrow

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What Happens To The Energy If I Dissolve A Compressed Spring ?
« Reply #14 on: 26/07/2009 22:35:57 »
Thats a good question.....I wwould think as the acid breaks down the spring tension would slowly be released as thespring disolved into the jar but I would suspect that the volume inside the jar may change and instead of spring pressure you may end up with air pressure in its place..so maybe when you opened the jar you may either have a pop or because of the acidic reaction you may have a gaseous situation where either the smoke from the metals breakdown in the acid may actually cause pressure maybe....?My brain is not to scientific.. am I even close...?
That's certainly a possibility.
 

Offline lightarrow

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What Happens To The Energy If I Dissolve A Compressed Spring ?
« Reply #15 on: 26/07/2009 22:56:11 »
Thanks sophiecentaur. So the energy will transfer as heat. Fascinating. I wonder if there is way to have a spring naturally decompose quickly in water to produce hot water ?....
You could make the spring with something (...springy enough) that dissolves in water, as sodium, potassium metal or an alloy of those kinds (with magnesium, aluminum, ecc.). Actually, the reaction itself would be exothermic and the energy released because of that would be in most cases greater than the spring's potential energy.
Maybe you could compress, let's say, a big NaCl crystal with a clamp and put it in water. Measure the temperature variation in the two cases: with and without compression and you can find if the elastic potential energy of the crystal has been converted into solution's internal energy (yes).

Quote
It's OK..it just dawned on me that maybe the energy involved in coiling the spring in the first place would be more than the energy released !..perhaps ?
No, in this case the conversion is 100%, because the initial energy (elastic potential) has been converted in a less 'useful' form.
« Last Edit: 26/07/2009 22:58:51 by lightarrow »
 

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What Happens To The Energy If I Dissolve A Compressed Spring ?
« Reply #15 on: 26/07/2009 22:56:11 »

 

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