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April 19, 2013, 00:27 |
What is specific heat really means
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#1 |
New Member
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I have confusion from my school days that why there is specific for everything..like specific heat,temp etc..pls help me with really meaning
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April 19, 2013, 02:48 |
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#2 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,208
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a wisely question.
Well,i think maybe several reasons be in existence each different in different cases. I have not heard specific temperature(in real gas theory?) But in some cases we want only dimensionless numbers so that probably simplifies our work during calculation or make it easier when do experiments or compare related cases,like specific length that can be the ratio of two lengths. Or a quantity in a period of time or divided by a quantity of mass,like specific heat(J/kg.K). In some cases maybe we only want a name for a concept.as an example specific volume is only reciprocal of density. Want anyone contribute in this argument or my speech is complete? |
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April 19, 2013, 05:09 |
Oh yeah..yes
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#3 |
New Member
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However I still cant understand...You said some used for concept sake..your example is j/kg k..and why do we need to do that...like specific volume.
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April 19, 2013, 06:22 |
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#4 |
Senior Member
Philipp
Join Date: Jun 2011
Location: Germany
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You can have an amount of heat Q stored inside a block of 2.3kg metal. Now, proportional to this heat Q is the heat capacity of the 2.3kg block C~Q. But this is just the heat capacity of a 2.3kg block. If you want to know the ability of that metal to store heat, you divide C by the mass of the block. Than you get the specific heat capacity. This is a material's property an not any longer the property of any special sized block. So if you are interested in material properties you need these "specific" values.
I guess you can use this explanation for most of the "specific ..." cases.
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April 19, 2013, 07:42 |
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#5 |
New Member
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Yes now explain specific volume.is the sa
me concept as specific heat ..specific volume also material properties |
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April 19, 2013, 07:49 |
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#6 |
Senior Member
Philipp
Join Date: Jun 2011
Location: Germany
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Sure... volume of a 0.1m cube of water is 1e-3m^3 or just 1 liter. The mass is about 1 kg. The materials property is volume per mass = specific volume. It's always the same value for water, whether you take any cube, sphere or whatever.
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April 19, 2013, 09:21 |
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#7 |
New Member
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So to find the capacity of 1 cubic volume of liquid to store is specific volume...like ah ...heat storing capacity of a metal..volume/mass
Am I got it correctly.. |
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April 19, 2013, 10:08 |
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#8 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,208
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well always its not related to property of a material.
like specific enthalpy is enthalpy per mass flow rate of fluid(1kg/s for example) or specific work(specific work=work/m_dot)that is related to flow of fluid(enthalpy that 1kg of a fluid transfers in 1 second or work 1kg of a fluid does or is done on it in 1s) not the material.but in overall it is correct. totally can say when we want to know how much a quantity we have per length,mass or mass flow rate we use the expression of specific xxx. Last edited by immortality; April 19, 2013 at 11:48. |
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April 19, 2013, 10:39 |
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#9 |
New Member
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Yep I got that...thank you..specific always to measure quantity and capability of what we take..that's so specific explanation
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