Does close systems really exist?

[nouveau_riche]

can anyone give me an example of isolated closed system?,bcoz for me there is nothing called closed system,all we can make out is to reduce the temperature of a system to such a critical point that there's hardly any interaction/exchange of energy b/w system and enviroment

 

[Hootenanny]

can anyone give me an example of isolated closed system?,bcoz for me there is nothing called closed system,all we can make out is to reduce the temperature of a system to such a critical point that there's hardly any interaction/exchange of energy b/w system and enviroment

Depends whether you mean a closed system, or an isolated system. One can find many examples of the former, but there are no known examples of the latter.

 

[arildno]

well, if the typical magnitude of internal changees over the time interval we are observing are much greater than the magnitude of what is lost/gained at the boundaries, the observed system can be regarded as roughly closed during the time interval of our observation.

 

[nouveau_riche]

well, if the typical magnitude of internal changees over the time interval we are observing are much greater than the magnitude of what is lost/gained at the boundaries, the observed system can be regarded as roughly closed during the time interval of our observation.

i don't need a rough approximation ,can u give an example of any closed system ?

 

[nouveau_riche]

Depends whether you mean a closed system, or an isolated system. One can find many examples of the former, but there are no known examples of the latter.

give examples of former but with the reason signifying it's name as "closed"

 

[Hootenanny]

give examples of former but with the reason signifying it's name as "closed"

Why do you want examples? It is more important to understand the difference between "closed" and "isolated" systems.

A closed system is one in which mass is conserved and cannot be transferred across the boundary. An isolated system is one in which both mass and energy cannot be transferred across the boundary.

 

[nouveau_riche]

Why do you want examples? It is more important to understand the difference between "closed" and "isolated" systems.

A closed system is one in which mass is conserved and cannot be transferred across the boundary. An isolated system is one in which both mass and energy cannot be transferred across the boundary.

if u know the difference u could also give me an example

 

[Hootenanny]

if u know the difference u could also give me an example

I could, but I suspect that this is a homework question and I do not want to do your homework for you.

How about this: You have a think about the definitions I gave above and try to come up with some examples. I will then tell you if they're right or wrong.

 

[nouveau_riche]

I could, but I suspect that this is a homework question and I do not want to do your homework for you.

How about this: You have a think about the definitions I gave above and try to come up with some examples. I will then tell you if they're right or wrong.

firstly ,it's not my homework question,i never do my homework
secondly...i asked for the example bcoz i don't think there a system(closed) that could go from order to disorder without interacting with it's surroundings

 

[Hootenanny]

firstly ,it's not my homework question,i never do my homework

Er...okay.

secondly...i asked for the example bcoz i don't think there a system(closed) that could go from order to disorder without interacting with it's surroundings

And this is why is it vitally important to undertsand the difference between a closed system and an isolated system. A closed system doesn't exchange mass with its surroundings, but that doesn't mean it doesn't interact with its surroundings! Consider the following example. I have a sealed box with a deck of cards neatly stacked in the centre. I now shake the box so that the cards scatter inside the box. No mass has been exchanged between the box and its surroundings, but the system is now in a more disordered state that it was initially.

Notice that the second law of thermodynamics refers to an isolated system, rather than a closed system.

 

[nouveau_riche]

And this is why is it vitally important to undertsand the difference between a closed system and an isolated system. A closed system doesn't exchange mass with its surroundings, but that doesn't mean it doesn't interact with its surroundings! Consider the following example. I have a sealed box with a deck of cards neatly stacked in the centre. I now shake the box so that the cards scatter inside the box. No mass has been exchanged between the box and its surroundings, but the system is now in a more disordered state that it was initially.

Notice that the second law of thermodynamics refers to an isolated system, rather than a closed system.

the order of disorder however depends upon the way in which the box is shaken,so the system undergoes interaction,thus system is not isolated...
i am not sure for this"does second law of thermodynamics require that a system should be left onto itself?"
or
second law of thermodynamics is applicable only to those systems which are left onto themselves ?

 

[Lil_Aziz1]

the order of disorder however depends upon the way in which the box is shaken,so the system undergoes interaction,thus system is not isolated...
i am not sure for this"does second law of thermodynamics require that a system should be left onto itself?"
or
second law of thermodynamics is applicable only to those systems which are left onto themselves ?

He never said it was isolated. he said it was closed.

 

[Dale]

There are lots of examples of closed systems:
A sealed mylar balloon
A piston when the valves are closed
A sealed soda can
A light bulb
Basically anything that is impermeable and physically closed is thermodynamically closed.

 

[nouveau_riche]

i am not sure for this"does second law of thermodynamics require that a system should be left onto itself?"
or
second law of thermodynamics is applicable only to those systems which are left onto themselves ?

 

[Hootenanny]

i am not sure for this"does second law of thermodynamics require that a system should be left onto itself?"
or
second law of thermodynamics is applicable only to those systems which are left onto themselves ?

I'm afraid that I don't understand.

 

[skanda9051]

can anyone give me an example of isolated closed system?,bcoz for me there is nothing called closed system,all we can make out is to reduce the temperature of a system to such a critical point that there's hardly any interaction/exchange of energy b/w system and enviroment

there is no ideal closed system but wool or cotton can be nearer to perfect closed system

 

[Hootenanny]

there is no ideal closed system but wool or cotton can be nearer to perfect closed system

There certainly are many, many examples of real physical closed systems. I suggest that you see my previous posts regarding isolated vs. closed systems.

 

[Dale]

And my post with several examples of closed systems. They are all over the place. There is no doubt that not only do closed systems exist, they are actually quite common.