Solution System boundary Energy balance: AKE APE AU-6-W Metal bar: Water: Tmi =1200K Twi =300K △water+△metal=0 Cm =0.42 kJ/kg-K Cw =4.2 kJ/kg.K mm =0.3 kg mw =9 kg mwCw(Tr-Twi)+mmCm(Tr-Tmi)=O (T:final equilibrium temperature) mw(Cw/Cm)Twi mmTmi T= mw(Cw/cm)+mm (9kg10)(300K)+(0.3kg(1200K) (9kg10)+(0.3kg) =303K 上游充通大 April 23,2019 7 SHANGHAI JLAO TONG UNIVERSITYApril 23, 2019 7 Solution Energy balance: (Tf : final equilibrium temperature)