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#11
Saturday, February 18, 2012
 Senior Member Join Date: Oct 2011 Location: دیار ِ آرزو Posts: 255 Thanks: 258 Thanked 244 Times in 152 Posts

Quote:
 Originally Posted by chemguy @Da Skeptik The average K.E. is independent of the size of the body. Even though the sea has trillions of molecules, when you take an average, it is the median K.E. of only one molecule. You see, the 'sea' has much greater 'total' K.E., but its average is paltry.
Dear Bro, I have never, in any post, argued that average K.E is dependent on the size of the body.. And Average is not the median of only one molecule but median of all the molecules..
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#12
Saturday, February 18, 2012
 Senior Member Join Date: Oct 2010 Location: Pakistan , punjab and city of shrines Posts: 1,456 Thanks: 1,406 Thanked 1,172 Times in 650 Posts

Quote:
 Originally Posted by Da Skeptic This example also shows that Temperature is not a measure of Heat..Again referring to the Same example I gave earlier, a Sea has more heat but less temperature..
first temprarture is measure heat .how how building is constructed .it is by dint of bricks .so brick is a unit .so one can says heat is little unit or it is the matter that is being placed .and when building is constructed .All bricks formed building .by this way All heat in particular object is contained .thy form of energy move unless equilibrium is established .In sea there is equilibrium of heat so it measures less hot and it also depends uopn the size of object too . when cup has full of water ,pouring more water will fall .this would not happen in case of heat .rather it will condense and become compact.so little object have higher density level of heat as compared to sea .that why it measures so hot. heat is quantity of matter and its intnse being is measured by scale called temperature scales .its not only celsuis but farehiet and kelvin too .we use many devices but mostly thermometr is used .now another related question to yours is

"why mercury is used in thermometr not water"
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#13
Saturday, February 18, 2012
 Senior Member Join Date: Nov 2010 Posts: 106 Thanks: 21 Thanked 74 Times in 50 Posts

@Da Skeptic

Temperature IS related to heat, here's why:

Take a sea and put in it a thermometer. The temperature reading will be close to atmospheric temperature. Right?

Now you take a cup of tea, and put in it a thermometer. The temperature will be higher.

Your argument is that the heat in sea is higher compared with the heat in tea. But this is not true. Let me explain.

When we measure heat, we don't measure the energy in the body, we measure the energy that moves. So, if you put the thermometer in sea, the energy that moves from water to mercury (Which then increases K.E. of mercury molecules causing them to rise) is heat. This is very small. If a large amount of heat had transferred in case of sea then we would have seen mercury rise even higher.

So in fact the heat is GREATER in case of tea than sea.

Another concrete reason is Newton's Law of Cooling which states that "Rate of heat transfer is directly proportional to the temperature difference", this means that the greater the DIFFERENCE of temperature between mercury and sea/tea, the MORE will be heat transferred.

You have confused the concept of Heat with Kinetic Energy and Potential Energy. Because the K.E. and P.E. of sea are indeed higher than those of tea.

Let me say it again, heat is the energy in move. Nothing possess heat.
#14
Saturday, February 18, 2012
 Senior Member Join Date: Nov 2009 Location: Karachi Posts: 443 Thanks: 416 Thanked 345 Times in 197 Posts

Quote:
 Originally Posted by Da Skeptic @Azeegum M here too to discuss what I think I know, brother.. Yep Heat and Temperature are very closely inter-related, when Total increases, the Average also increases.. What I differ is that Temperature is not a measure of Heat.. An Average can not be the measure of the Total.. I had given the example of Sea and Tea.. Though Sea has less temperature but more Heat as compared to a cup of Hot Tea.. If temperature would have been a measure of Heat, the temperature of the Sea must have been greater than that of a cup of Hot Tea..
By the way bro, what do you understand of the word measure here? I guess you think it means "multiple", and when I say "a measure of heat" what probably comes to your mind is "a multiple of heat". Right?
Let me make it clear... Measure means number or degree, not multiple dost.
The example of sea and a cup of hot tea makes sense here when it comes to the difference between heat and temperature but you are trying to relate the phenomenon in a wrong way. True, sea may have more energy than a hot cup of tea but less temperature comparatively, BUT it does not totally conform to the definitions put forward by you. In fact both are as different as chalk and cheese. I guess you need to study both over again. And your adamant refusal to accept the definitions inspite of having been provided with the authenticated references, has led me to study heat and temperature over again. To check if I was wrong anywhere I had a study of heat and temperature for half an hour just a little earlier, and what I have come up with is that the definitions of both heat and temperature as put forward by you are wrong. I have already detailed about temperature. I have elaborated heat in detail in reply to chemguy's post below. Read it carefully.
I can rattle of a thousand more references to prove that heat is a form of energy and temperature a measure of it. Can you just provide me only reference to prove me wrong? Please do me this favour.

Quote:
 Originally Posted by chemguy So the actual definition is "Heat is the transfer of energy due to temperature difference."
Well, you have also defined the term 'heat' incompletely here.
It's not just transfer of energy that takes place when it comes to heat, but the production of heat also. Heat does not only occur when it flows from a hot body to a cold body, but also produced through friction, viscosity, or chemical reactions etc. Let me give you an example of heat by friction here.
Rub your both hands vigorously with each other. Make sure that both of your hands are cold. You'll observe that your both hands warm up. This is because the average kinetic energy of molecules increases as the result of rubbing, which in turn increases temperature.
This proves that heat does not only occur by transfer from a hot body to a cold body but also by production. And in case of hands, none of both is hot- both are cold.
The foregoing example also elaborates that temperature is directly proportional to the average kinetic energy of molecules, that is the temperature increases if the average kinetic of molecules increases.
Other example can be given that of chemical reactions like respiration in human body. During respiration, carbohydrates are oxidised and as the result carbon dioxide, water and energy are produced.
This also proves that heat is produced, not just transferred because of temperature difference.
So the complete definition of heat goes as
"Heat is energy produced or transferred from one body, region, set of components, or thermodynamic system to another in any way other than as work."
So, the transfer of heat takes place through conduction (also called diffusion), convection, or radiation, etc. While the production of heat can take place through friction or viscosity or chemical reactions etc.
The definition given by you is correct when it comes to a closed system (with no external transfer of matter) but here we are talking about heat in general.
Correct me if I am wrong.

Quote:
 Originally Posted by chemguy Another concrete reason is Newton's Law of Cooling which states that "Rate of heat transfer is directly proportional to the temperature difference", this means that the greater the DIFFERENCE of temperature between mercury and sea/tea, the MORE will be heat transferred. Let me say it again, heat is the energy in move. Nothing possess heat.
Newton's Law of Cooling states that "Rate of heat transfer is directly proportional to the temperature difference". True, but the said law only talks about convection of heat which is one of the ways how heat transfers from a hot region to a cold region. 'Heat can also be produced' is still missing in your account.

And in your last sentence, let us replace the term "energy in move" by energy in flow or flow of energy or transfer or energy or energy transfer, because it gives an impression to mean energy in motion. And we know energy is never in motion. Even when it comes to kinetic energy, it's not the energy itself that is in motion but the object in motion is said to possess kinetic energy. For example, a bullet passing an observer has kinetic energy.

PS: Thank you guys for making me read heat and temperature over again and giving me chance to make my pitch on the topic. I don't mind being corrected. So you can point out if I am wrong.

Regards
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#15
Sunday, February 19, 2012
 Senior Member Join Date: Oct 2010 Location: Pakistan , punjab and city of shrines Posts: 1,456 Thanks: 1,406 Thanked 1,172 Times in 650 Posts

sea K:E is more and cup has less.more K:E stands for more evaporation and higher the rate mean lowering the temperature of subject .so sea has high rate of evoporation whereas cup has less .tha`s why it is more hot as compared to sea
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#16
Sunday, February 19, 2012
 Senior Member Join Date: Nov 2010 Posts: 106 Thanks: 21 Thanked 74 Times in 50 Posts

Sea's total K.E. is indeed more (Because of the size) but if you were to compare the K.Es of one molecule of sea and one molecule of tea, the Kinetic energy of the molecule of tea will more more. A system's total K.E. is not the only indicator of rate of evaporation, it also depends on size of system. The reason there is more evaporation is because of sea's surface area. If you pour tea on ground it will too evaporate faster.

@Azeegum:

I agree that heat can be made from friction and viscosity. And heat can come from many other sources, I guess in my ignorance I was forcing my limited study of heat (thermodynamic perspective) to be the only meaning of heat.

I still like my definition better because for all practical purposes in thermodynamics it rules! Wikipedia:

Quote:
 In a thermodynamic sense, heat is never regarded as being stored within a system. Like work, it exists only as energy in transit from one system to another or between a system and its surroundings. When energy in the form of heat is added to a system, it is stored as kinetic and potential energy of the atoms and molecules in the system.[
"Heat is energy produced or transferred from one body, region, set of components, or thermodynamic system to another in any way other than as work."

Your definition is incomplete because if you think about light energy, it can be transferred without any work.

Quote:
 And in your last sentence, let us replace the term "energy in move" by energy in flow or flow of energy or transfer or energy or energy transfer, because it gives an impression to mean energy in motion. And we know energy is never in motion. Even when it comes to kinetic energy, it's not the energy itself that is in motion but the object in motion is said to possess kinetic energy. For example, a bullet passing an observer has kinetic energy.
What about heat transfer through radiation? Take the whole light spectrum, VIBGYOR along with U.V. and Gamma

Newton's Law of Cooling:

Newton's Law of Cooling is a very general law and it is not limited to convection. It accounts for all 3 modes of heat transfer because
it has only 2 parameters 'Temperature' and 'Time'. And if you know a body's initial temperature, you can calculate its 'k' a constant unique to it which is its overall ability of heat transfer, you can calculate its temperature sometime in future.

P.S.:We're splitting hair here :p The original question has been answered several times. But bro, thanks for clarifying this concept!
#17
Sunday, February 19, 2012
 Senior Member Join Date: Oct 2010 Location: Pakistan , punjab and city of shrines Posts: 1,456 Thanks: 1,406 Thanked 1,172 Times in 650 Posts

Quote:
 Originally Posted by chemguy @Sadia Shafiq: Sea's total K.E. is indeed more (Because of the size) but if you were to compare the K.Es of one molecule of sea and one molecule of tea, the Kinetic energy of the molecule of tea will more more. A system's total K.E. is not the only indicator of rate of evaporation, it also depends on size of system. The reason there is more evaporation is because of sea's surface area. If you pour tea on ground it will too evaporate faster. !
sea has more heat because it has more material .so more molecules will have larger flow as compare to cup .why example of cup and tea has given if one molecule of both have to comapre ?? sea P:E converted into K:E and flow /energy helped in evaporation .that`s why avaerage temerature of sea is changing .that`s why sea or cup hotness is measured by scale and scale is formulated on the basis of P:E and K:E .look when heat packects are increased w.r.t object then process of evaporation take place .cup size is small and kettle has larger size .pour equal amount of boiled water/tea in both .kettle temperature will fall immediately but cup of tea reamined hot? why ...just molecules escaped from the surface of kettle more quickly having equal amount of tea. and if kettle take 5 mins to cool down then cup will take 15 mins.it means cup is more hot or it contained more heat .no cup heat could not be converted easily into vapours
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#18
Sunday, February 19, 2012
 Junior Member Join Date: Sep 2007 Location: USA Posts: 11 Thanks: 1 Thanked 3 Times in 3 Posts

Heat:
>Heat is the total energy of molecular motion in a substance.
>Heat energy depends on the speed of the particles, the number of particles (the size or mass), and the type of particles in an object.
>It is heat that will increase or decrease the temperature. If we add heat, the temperature will become higher. If we remove heat the temperature will become lower.

Temperature:
>Temperature is a measure of the average energy of molecular motion in a substance.
>Temperature does not depend on the size or type of object.
>Higher temperatures mean that the molecules are moving, vibrating and rotating with more energy and vice versa.
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 The Following User Says Thank You to shaki For This Useful Post: Da Skeptic (Tuesday, February 21, 2012)
#19
Sunday, February 19, 2012
 Senior Member Join Date: Nov 2009 Location: Karachi Posts: 443 Thanks: 416 Thanked 345 Times in 197 Posts

Quote:
 Originally Posted by chemguy @Azeegum: 1. I agree that heat can be made from friction and viscosity. And heat can come from many other sources, I guess in my ignorance I was forcing my limited study of heat (thermodynamic perspective) to be the only meaning of heat. 2. "Heat is energy produced or transferred from one body, region, set of components, or thermodynamic system to another in any way other than as work." Your definition is incomplete because if you think about light energy, it can be transferred without any work. 3. What about heat transfer through radiation? Take the whole light spectrum, VIBGYOR along with U.V. and Gamma Newton's Law of Cooling: Newton's Law of Cooling is a very general law and it is not limited to convection. It accounts for all 3 modes of heat transfer because it has only 2 parameters 'Temperature' and 'Time'. And if you know a body's initial temperature, you can calculate its 'k' a constant unique to it which is its overall ability of heat transfer, you can calculate its temperature sometime in future. P.S.:We're splitting hair here :p The original question has been answered several times. But bro, thanks for clarifying this concept!
You're misquoting and misunderstanding me here.
All three answers separately made by you to my posts are apparently self-contradictory. On the one hand you're admitting that heat does not only occur by transfer but also its production. On the other hand, you think that that definition of heat as given by me is incomplete. And yet in another answer, you're going against what you claim in your second answer.
First of all let us read the definition of heat here.
http://en.wikipedia.org/wiki/Heat Read the introductory lines of article.
Now let me make it more clear...
Heat is an energy transferred or produced by any means other than work. Work is an exception to it. I didn't mean that heat as caused by work is also termed as heat according to its standard definition.
And transfer of heat through radiation is spontaneous. And not just radiation, all other means of heat transfer like convection, conduction etc are spontaneous, that is they do not require to have been caused by work to be called as heat as given in definition.
Transfer of heat from sun to earth (ie radiation) is again a phenomenon of transfer of energy. It can not be termed as energy in motion or move. Energy does not move itself. To term energy in motion, is a tantamount to rejecting the standard definition of kinetic energy. Kinetic energy is defined as
"The Kinetic energy (KE) is the energy an object possesses because it is in motion. Moving cars, falling bricks, and vibrating molecules all have kinetic energy. Be careful: it is not energy in motion, or energy going from one place to another, it is the energy something has just because it is in motion."
Visit the source: Heat and Energy

Newton's Law of Cooling
No ! The said law only accounts for convection of heat.
Infact Newton's Law of Cooling particularly describes the cooling of a warmer object to the cooler temperature of the environment which is only carried out through convection. Convection is a mode of heat transfer through liquids and gases caused by molecules from hotter body to colder body and vice versa. Let us take for example holding your one hand above the flame of a candle and the other on one side of the flame at the same distance from the flame. The hand above the burner feels more heat than the other. This is because the hot gases from the flame rise when part of the gas is heated and the cold gas moves to take the place of hot gas. This phenomenon is known as convection of heat.
Other example can be given of the earth. At night, the land cools down more quickly than the sea. The hot air over the sea rises and cold air from the land takes its place. The cooling down of earth is convection and you can detect the temperature difference by applying formula of Newton's Law of Cooling. So, in case of Newton's Law of cooling, the temperature of a body drops down because heat flows out of it. The cooling of a hot coffee is also a case of convection. This law does not apply in case of heat conduction.
So in more elaborative terms, the complete definition of Newton's Law of Cooling goes as
"For a body cooling in a draft (ie by forced convection), the rate of heat loss is proportional to the difference in temperatures between the body and its surroundings."
Visit the reference: Newton's Law of Cooling -- from Eric Weisstein's World of Physics
If you still believe that Newton's Law of Cooling also talks about other modes of heat transfer like conduction or diffusion, radiation etc then just give me any example of heat conduction or radiation by applying Newton's Law of Cooling. I don't know if it is possible. If you can prove it then it will add to my knowledge.

And your last lines make me smile Don't worry we're not going to stumble into splitting hair of each other or of ourselves I share what I know and so does everyone including you. It's share and share alike you know.

Regards
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#20
Tuesday, February 21, 2012
 Senior Member Join Date: Oct 2011 Location: دیار ِ آرزو Posts: 255 Thanks: 258 Thanked 244 Times in 152 Posts

Quote:
 Originally Posted by azeegum The example of sea and a cup of hot tea makes sense here when it comes to the difference between heat and temperature but you are trying to relate the phenomenon in a wrong way. True, sea may have more energy than a hot cup of tea but less temperature comparatively, BUT it does not totally conform to the definitions put forward by you. In fact both are as different as chalk and cheese. I guess you need to study both over again. And your adamant refusal to accept the definitions inspite of having been provided with the authenticated references, has led me to study heat and temperature over again. To check if I was wrong anywhere I had a study of heat and temperature for half an hour just a little earlier, and what I have come up with is that the definitions of both heat and temperature as put forward by you are wrong. I have already detailed about temperature. I have elaborated heat in detail in reply to chemguy's post below. Read it carefully. I can rattle of a thousand more references to prove that heat is a form of energy and temperature a measure of it. Can you just provide me only reference to prove me wrong? Please do me this favour.
Here is the reference..
making sense of secondary science research into children's ideas (1994). By Rosalind driver, ann squires, peter rushworth, valerie wood-robinson. Chapter name, Heat, published by Routledge..
And every where, u have been giving ur own "intellectual analysis and interpretation", not references..
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