Work (w)

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504939134
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Joined: Wed Sep 18, 2019 12:21 am

Work (w)

Postby 504939134 » Sun Jan 26, 2020 9:49 pm

Why is work not a state property and what are different types of work?

Nare Nazaryan 1F
Posts: 101
Joined: Fri Aug 09, 2019 12:17 am

Re: Work (w)

Postby Nare Nazaryan 1F » Sun Jan 26, 2020 9:55 pm

Work (and heat) are not state functions. Work is proportional to the distance an object is moved, which depends on the path used to go from the initial to the final state (therefore not a state function). Usually doing things that require force and distance are considered as doing "work."

Anna Heckler 2C
Posts: 102
Joined: Wed Sep 18, 2019 12:18 am

Re: Work (w)

Postby Anna Heckler 2C » Sun Jan 26, 2020 10:06 pm

Work is not considered a state function because the amount of work done is dependent on more than just the initial and final values - it depends on the path taken to get from the initial to final values.

Alondra
Posts: 36
Joined: Tue Feb 26, 2019 12:15 am

Re: Work (w)

Postby Alondra » Sun Jan 26, 2020 10:18 pm

Work can be thought as the force or energy applied to something. Since the value of this force/energy varies by object it cannot be consider a state property.

DesireBrown1J
Posts: 98
Joined: Wed Sep 18, 2019 12:18 am

Re: Work (w)

Postby DesireBrown1J » Mon Feb 10, 2020 8:27 pm

There are other types of work but we only need to worry about expansion work for the midterm. Here is a table of other types of work that was in the textbook on page 245.

types of work.JPG

805394719
Posts: 104
Joined: Wed Sep 11, 2019 12:16 am

Re: Work (w)

Postby 805394719 » Mon Feb 10, 2020 9:35 pm

Work is not a state property because the work you have done does not depend on the difference between the final state and the initial state. For example, you may go up a hill along a straight path and you may also go up the hill in a rocky path that increases the distance between the ground and the top of the hill. If you choose the first way, you will walk less, spend less energy, and thus do less work. If you choose the other path, you will spend more energy. Therefore, work is not a state property because attaining the final state by one way may require more energy than the other way.

Aarushi Solanki 4F
Posts: 107
Joined: Sat Jul 20, 2019 12:17 am

Re: Work (w)

Postby Aarushi Solanki 4F » Mon Feb 10, 2020 9:37 pm

Work isn't a state property because the energy used when doing work is different based on the path to achieve the final state. When expansion work occurs reversibly, more work is done than if it were to be done irreversibly.

Joowon Seo 3A
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Joined: Sat Aug 24, 2019 12:17 am
Been upvoted: 1 time

Re: Work (w)

Postby Joowon Seo 3A » Mon Feb 10, 2020 11:34 pm

Work is not a state property because it depends on the path taken. If you walk a really roundabout path and a path straight from point a to point b you will spend a different amount of energy and do a different amount of work.

JesseAuLec1Dis1G
Posts: 52
Joined: Mon Jun 17, 2019 7:23 am

Re: Work (w)

Postby JesseAuLec1Dis1G » Tue Feb 11, 2020 12:13 am

Work is dependent on the path taken. If you're on a football field and you push a sled to the 50 yard line, then you go back to the 30 yard line you do more work than someone who just pushes a sled to the 30 yard line, even though you end up in the same spot.


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