I'm having a problem determining the total entropy change in a metal quenching problem. Here is the information I am given (subscript 'm' is for metal, 'w' is water):(adsbygoogle = window.adsbygoogle || []).push({});

m_{m}= 20 kg

m_{w}= 1000 kg

T_{1m}= 800 C

T_{1w}= 30 C

C_{pm}= .4 kJ/kg K

C_{pw}= 4.18 kJ/kg K

With this information, I found T_{2}to be 304.6 K.

How can I obtain the entropy change with this information? I have no pressure values, and all my entropy equations involve pressure, or specific volume which depends on pressure. Thanks for any help.

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# Thermodynamics - obtaining quenching entropy

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