U=q or U=q+w?


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JennyCKim1J
Posts: 51
Joined: Fri Sep 29, 2017 7:04 am

U=q or U=q+w?

Postby JennyCKim1J » Sun Jan 14, 2018 6:03 pm

When is the change in internal energy (U) equal to heat (q) and when is it equal to heat+work (q+w)? What is the difference between U=q and U=q+w?

PranithaPrasad
Posts: 58
Joined: Fri Sep 29, 2017 7:06 am
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Re: U=q or U=q+w?

Postby PranithaPrasad » Sun Jan 14, 2018 6:36 pm

so U is always U=q+w, so as I understand it, U=q when there is no work being done by or on the system.

Jonathan Tangonan 1E
Posts: 50
Joined: Sat Jul 22, 2017 3:01 am

Re: U=q or U=q+w?

Postby Jonathan Tangonan 1E » Sun Jan 14, 2018 7:41 pm

Yes this is true, the change in U= q + w. The change in internal energy is equal to the heat in the case that there are no other processes taking place except that of transferring energy as heat.

Nora 1F
Posts: 46
Joined: Fri Sep 29, 2017 7:04 am

Re: U=q or U=q+w?

Postby Nora 1F » Sun Jan 14, 2018 11:51 pm

If you're looking for an example of this, problem 8.53 is a good start.


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