From 7f60ea012dd2524dae921a2a35adbf7ef21f2bb6 Mon Sep 17 00:00:00 2001 From: prashantsinalkar Date: Tue, 10 Oct 2017 12:27:19 +0530 Subject: initial commit / add all books --- 3685/CH7/EX7.3/Ex7_3.sce | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 3685/CH7/EX7.3/Ex7_3.sce (limited to '3685/CH7/EX7.3/Ex7_3.sce') diff --git a/3685/CH7/EX7.3/Ex7_3.sce b/3685/CH7/EX7.3/Ex7_3.sce new file mode 100644 index 000000000..c61883f58 --- /dev/null +++ b/3685/CH7/EX7.3/Ex7_3.sce @@ -0,0 +1,27 @@ +clc +// Part (a) +m = 1 // Mass of ice in kg +T1 = -5 // Initial temperature of ice in degree Celsius +T2 = 20// Atmospheric temperature in degree Celsius +T0 = 0// Phase change temperature of ice in degree Celsius +cp = 2.093 // Specific heat capacity of ice in kJ/kgK +cv = 4.187 // Specific heat capacity of water in kJ/kgK +lf = 333.3 // Latent heat of fusion in kJ/kgK + +printf("\n Example 7.3") +Q = m*cp*(T0-T1)+1*333.3+m*cv*(T2-T0) // Net heat transfer +Sa = -Q/(T2+273) // Entropy change of surrounding +Ss1 = m*cp*log((T0+273)/(T1+273)) // entropy change during +Ss2 = lf/(T0+273) // Entropy change during phase change +Ss3 = m*cv*log((T2+273)/(T0+273)) // entropy change of water +St = Ss1+Ss2+Ss3 // total entropy change of ice to convert into water at atmospheric temperature +Su = St+Sa // Net entropy change of universe +printf("\n The entropy change of the universe is %f kJ/K",Su) + +//The answer provided in the textbook is wrong +// Part (b) +S = St // Entropy change of system +Wmin = (T2+273)*(S)-Q // minimum work required +printf("\n The minimum work required is %f kJ",Wmin) +//The answers vary due to round off error + -- cgit