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 ram August 9, 2000 04:19

entropy!!!!!!1

hi.. why does anyone explain that the entropy appears to be a abstract concept compared to other calculabe quantities like energy, work and other measurable quantites like temperautre , pressure ?

thanks

ram

 mehdi ben elhadj August 9, 2000 05:32

Re: entropy!!!!!!1

Hi,

Entropy can be defined as the measure of dissorder a system contains. One way to calculate entropy is to use a formula Ludwig Boltzman came up with:

S = k ln W

Where k is Boltzman's constant : k = 1.381 * 10-23 J/K

W represents the number of different ways in which energy of a system can be rearranged.

So, it's clear that entropy isn't "A Result" compared to other calculabe quantities like energy, work and other measurable quantites like temperautre .

 ram August 10, 2000 03:33

Re: entropy!!!!!!1

Thank you..but i have one more thing . why does entropy appear to be a ABSTRACT concept compared to other comcepts ?

Regards

Ram

 clifford bradford August 10, 2000 17:08

Re: entropy!!!!!!1

i think you've made the point. most properties of substances can be directly measured (or at least appreciated) in many cases by one of our five senses. Entropy is sensibly non-evident and can't be measured by any device. even quantities like magnetic field can be detected by various devices and visualized by iron filings etc. but entropy can only be calculated and it is one of the few quantities that has this characteristic. moreover it is tricky to pin down the entropy state of substance: we can often make accurate statements regarding it like hot air has a higher entropy than cold air at the same pressure but in general it's not necessarily easy to make such comparisons.

 ram August 12, 2000 06:48

Re: entropy!!!!!!1

thank you for the clarification..

ram

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