作者tina791216 (豆豆)
看板Physics
标题[问题] 一题热力学观念请教(entropy)
时间Sat Oct 19 20:37:17 2013
题目如下:
Two equal quantities of water , each of mass m and at temperature T1 and T2,
are adiabatically mixed together , the pressure remaining constant.
Show that the entropy change of the universe is
ΔS=2mCp ln( (T1+T2) / (2(T1T2开根号)))
我有算出来 但我对观念部分有点疑虑
在这里是求ΔS universe
ΔS universe = ΔS system + ΔS surrounding
我的想法是:
因为绝热 所以ΔS surrounding=0
而ΔS system=不可逆ΔS (如答案所示)
假如系统可逆的话 ΔS system = dQ/T
是这样吗?
总觉得怪怪的 想上来确定一下观念是否正确 感谢!
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1F：推 ray3839139:没错 10/19 23:25