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diff --git a/1752/CH4/EX4.7/exa_4_7.sce b/1752/CH4/EX4.7/exa_4_7.sce
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+//Exa 4.7
+clc;
+clear;
+close;
+//given data
+k=380;// in W/mK
+delta =6*10^-2;// thickness of plate in meter
+rho=8800;// kg/m^3
+C=400;// J/kg-K
+// l_s= V/A = delta/2
+l_s= delta/2;// in meter
+t=80;// in degree C
+t_i=200;// in degree C
+t_inf=30;// in degree C
+hw= 75;// in W/m^2K
+ha= 10;// in W/m^2K
+
+// Part(i)
+// ha*A*(t-t_inf_a)+ hw*A*(t-t_inf_w) = -rho*V*C*dtBYdtho, since t_ini_a = t_inf_w = t_inf = 30 degree C
+// (ha+hw)*A*(t-t_inf)= -rho*V*C*dtBYdtho
+// (ha+hw)/(rho*C*V)*A*dtoh = -dt/(t-t_inf)
+// integrate('(ha+hw)/(rho*V*C)*A','toh',0,toh) = integrate('1/(t-t_inf)','t',t_i,t)
+toh= -rho*l_s*C/(ha+hw)*log((t-t_inf)/(t_i-t_inf));
+disp("Time required to cool plate to 80 degree C is : "+string(toh)+" seconds = "+string(toh/60)+" minutes");
+
+// Part (ii)
+t= -rho*l_s*C/(2*ha)*log((t-t_inf)/(t_i-t_inf));
+disp("Time required to cool plate in only air is : "+string(t)+" seconds = "+string(t/60)+" minutes");
+