Question

50kg steel casting initially at 390°C was closed in the container which contains 110kg of oil initially at 15°C. During cooling process heat equaled to 15% of the change of intemal energy of steel casting flowed away from the container to the surroundings at 15°C Calculate entropy generated during cooling process to the moment when the temperatures of steel cast and oil are the same. Specific heats of steel and oil are equaled to: 0.5 and 2.5kJ/(kgK), respectively.

Answer 1

390 C 5o k stl Cashny 663 K at is 110 at 1 S°c 988 K K3 Arecitic hut K Coil 2-S let nal Temp isT then chanye in teanl enery of de in LP Su m.51T-663 tarfeue to nding (15) 0-15 Xm,es enery 17 hut eauainm m,st m.cT 01FmC - ms s Ts t moG T,+0-15m, CT 1.15 mss t m, C 110 x2.5 X 288 Sx01l tsoux.sI

190 01.25 +79200 98261.25 303-75 Sして+SL8て 3 23.49 K 7= Ms (c3-T Tsuo 0-IS + +m. dn /T AS 50メ 0.5x (-0-7176)+11072-5X(o-162) ニ-17-940 + 31.957+4.42) 19-438 丁1K