Final 2015 Question #3


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JukaKim_1D
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Joined: Fri Sep 25, 2015 3:00 am

Final 2015 Question #3

Postby JukaKim_1D » Thu Mar 10, 2016 10:59 am

When the question asks, what is the work DONE by the air in the lungs as it expands on going from 20C to 37C,
even though the calculation would be -3.9J (in terms of the system), shouldn't the answer be 3.9J? Because "doing work" and the negative sign cancels out each other in terms of definition?

Chem_Mod
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Re: Final 2015 Question #3

Postby Chem_Mod » Thu Mar 10, 2016 12:22 pm

Remember that work DONE by something meaning it's losing its energy to do work which is demonstrated by the "-" sign.

JukaKim_1D
Posts: 24
Joined: Fri Sep 25, 2015 3:00 am

Re: Final 2015 Question #3

Postby JukaKim_1D » Thu Mar 10, 2016 12:24 pm

yeah so wouldn't it make sense to say 3.9J of work was done?


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