open system

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Mariane Sanchez 1E
Posts: 57
Joined: Fri Sep 29, 2017 7:07 am

open system

Postby Mariane Sanchez 1E » Thu Jan 18, 2018 9:09 pm

so in lecture today dr. lavelle talked about how you can change the energy of a system if you add or subtract substance from the system. how so?

Salman Azfar 1K
Posts: 50
Joined: Thu Jul 13, 2017 3:00 am

Re: open system

Postby Salman Azfar 1K » Thu Jan 18, 2018 9:37 pm

One method is to say, evaporate water in an open beaker. Basically some of the substance leaves the system.

Christy Zhao 1H
Posts: 50
Joined: Fri Sep 29, 2017 7:07 am

Re: open system

Postby Christy Zhao 1H » Thu Jan 18, 2018 10:46 pm

Another example is an uncovered pot of hot water. Matter is leaving the system through the steam, and energy as heat is also lost.

William Xu Dis 1D
Posts: 31
Joined: Fri Sep 29, 2017 7:05 am

Re: open system

Postby William Xu Dis 1D » Thu Jan 18, 2018 11:17 pm

The way I see it is that as noted in the textbook, matter has internal energy (U) which includes the energy of an atom, its electrons, protons, neutrons, and the bonds it forms with other atoms. All of this is energy within the matter, so when it is removed, energy is subtracted

Yu Chong 2H
Posts: 30
Joined: Fri Sep 29, 2017 7:05 am

Re: open system

Postby Yu Chong 2H » Fri Jan 19, 2018 2:21 pm

All matter have their own internal energy, removing a unit of matter from a system means removing part of the internal energy that the system has.

Brigitte Phung 1F
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Joined: Thu Jul 27, 2017 3:00 am
Been upvoted: 1 time

Re: open system

Postby Brigitte Phung 1F » Fri Jan 19, 2018 2:38 pm

In all systems, the matter/substance involved in the system contributes to its energy. Because matter can be exchanged with the surroundings of an open system, the addition or removal of substance from the system can change its energy.

Kyung_Jin_Kim_1H
Posts: 53
Joined: Thu Jul 27, 2017 3:00 am

Re: open system

Postby Kyung_Jin_Kim_1H » Sat Jan 20, 2018 8:09 pm

Another way to think of it is to think of a mug of steaming hot chocolate cool down. The hot chocolate/mug lost energy and the surroundings gained energy in form of heat.


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