Recent content by asdf188

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    Total change in entropy, what am I doing wrong?

    The answer is 0.94 J/K. But I have no idea how he got there. the C for alum from our book is .22 so I got .22ln(324K/286K) + 1ln(324K/331K) = .006071 J/K I am still missing something aren't I?
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    Total change in entropy, what am I doing wrong?

    Using your formula I have 691.796 J/K from 900ln(51/13) + 4186ln(51/58) but I am still wrong in my answer. Am I supposed to convert to Kelvins? or use kcal/kg?
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    Total change in entropy, what am I doing wrong?

    120 g insulated aluminum cup at 13°C is filled with 140 g of water at 58°C. After a few minutes, equilibrium is reached. I found the final temperature to be 51°C. But I am having trouble finding the total change in entropy. I was using 13°C = 286.15°K 51°C = 324.15°K 58°C =...
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    Total change in entropy, what am I missing?

    A 20.0 -kg box having an initial speed of 1.0 m/s slides along a rough table and comes to rest. Estimate the total change in entropy of the universe. Assume all objects are at room temperature (293 K). I don't understand how to answer this problem. It feels like I wasn't given enough...
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