High School Physics Competition: Change in Entropy

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Homework Help Overview

The discussion revolves around a physics competition question regarding the calculation of change in entropy when heat is added to a system at a constant temperature. The original poster attempts to apply the formula for entropy change, but encounters confusion regarding the interpretation of answer choices.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • The original poster calculates the change in entropy using the formula ΔS = Q/T and presents their result. They express uncertainty about the meaning of one of the answer choices, specifically the use of a hashtag.

Discussion Status

Some participants affirm the original poster's calculation and suggest that the change in entropy is positive. Others clarify the meaning of the hashtag in the answer choices, indicating it represents a negative value.

Contextual Notes

The original poster is working under the constraints of a competition setting, which may impose specific answer formats or interpretations that are not immediately clear.

ReneG
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During a physics competition, I came across this question.
What is the change in entropy of the system when 1.25 " 103 J of heat is added to the system that is maintained at a constant 75.0 C?

My work was
\begin{align*}\Delta S &= \frac{Q}{T} \\ \Delta S &= \frac{1.25 \times 10^3 \, \mathrm{J}}{348 \, \mathrm{K}} \\ \Delta S &= 3.59 \,\,\mathrm{\left( J/K\right )} \end{align*}

but I was stuck in between two answer choices

c) + 3.59 J/K
d) # 3.59 J/K

I had no idea what the hashtag meant, so I skipped it. Can someone clear this up for me?
 
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Honestly I have no idea, but certainly the change in entropy is positive, so answer c) is correct. Maybe it's a misprint?
 
I guess what dipole said it's right 'cause it sometimes happens
 
Last edited:
For anyone who was wondering, the hashtag just meant "negative". Thank you dipole.
 

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