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### Difference between systems?

Posted: Sun Jan 28, 2018 8:05 pm
Can someone please explain the exact definitions of open, closed and isolated systems?

### Re: Difference between systems?

Posted: Sun Jan 28, 2018 8:11 pm
Closed has a fixed amount fo energy but it can exchange energy with its surroundings (cold pack)
Open can exchange both matter and energy with the surroundings (human body)
Isolated has no contact with its surroundings (thermos)

### Re: Difference between systems?

Posted: Sun Jan 28, 2018 9:16 pm
An open system freely exchanges energy and matter with its surroundings. The simplest example of this is boiling water, where both water can leave in the form of vapor and it gives off heat. A closed system only exchanges energy with its surroundings, so this is like boiling water with a lid on. You've now prevented the water vapor from escaping your system, but the pot is still hot and making its surroundings hotter.

And an isolated system doesn't exchange anything with its surroundings. So ideally, a thermos is supposed to keep whatever you put in it at the same temperature and the material inside can't get out either.

### Re: Difference between systems?

Posted: Sun Jan 28, 2018 9:19 pm
Is a thermos still considered an isolated system if a person drinks from it?

### Re: Difference between systems?

Posted: Sun Jan 28, 2018 9:41 pm
Once a person opens the thermos to drink, it becomes an open system, as both mass (the water) and energy (heat) can flow from the system to the surroundings and vice versa.

### Re: Difference between systems?

Posted: Sun Jan 28, 2018 10:11 pm
An open system can exchange both matter and energy with its surroundings. A closed system can only exchange energy with its surrounding but not matter. An isolated system cannot exchange neither energy nor matter given the fact that it lacks any contact with its surroundings.

### Re: Difference between systems?

Posted: Sun Jan 28, 2018 10:14 pm
Kennedy is correct about the thermos. It is isolated until it is opened for a drink then it becomes an open system. When the drink is taken and done and the bottle is closed again, the system is re-isolated. The system will go to equilibrium at a new temperature/heat that may not be the same as it was before it was opened to exchange matter and energy with the surroundings.

### Re: Difference between systems?

Posted: Mon Jan 29, 2018 10:09 pm
Open system - exchange energy and matter
Closed system - exchange only energy not matter
Isolated system - cannot exchange energy nor matter

### Re: Difference between systems?  [ENDORSED]

Posted: Sat Feb 03, 2018 2:03 pm
An open system can transfer matter and/or energy. A closed system system can transfer energy not matter. An isolated system cannot transfer either.