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In moving out of a dormitory at the end of the semester, a s

  • Thread starter Alice7979
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Homework Statement


In moving out of a dormitory at the end of the semester, a student does 2.62 x 10^4 J of work. In the process, his internal energy decreases by 3.96 x 104 J. Determine each of the following quantities (including the algebraic sign): (a)W, (b)
upper_delta.gif
U, and (c)Q.

Homework Equations


b) ∆U = Q-W

c) if the system does work its positive, if the system has work done on its negative

The Attempt at a Solution


I got (a) right, it is 2.62 x 10^4 J

b)
-3.96E4 - (2.62E4) = -65800

c)
-3.96E4 but I'm not sure about if it is negative or positive

And does the algebraic sign just mean + or -?
 

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Answers and Replies

  • #2
Nathanael
Homework Helper
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And does the algebraic sign just mean + or -?
Yes (as opposed to giving just the absolute value).
In the process, his internal energy decreases by 3.96 x 104 J.
This is the number you give for part c.
So the change in internal energy is Q?
 

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