Calculate the temperature distribution in a $1-$D fin, the fin is rectangular in shape and is $120$ mm long, $40$ mm wide and $10$ mm thick. One end of the fin is fixed and other end is free. Assume that convection heat loss occurs from the end of the fin. Use $2$ elements. The temperature at fixed end is$120$ oC$,$ h $=10-3$ W$/$mm oC$,$ K $=0\mathrm{.}3$ W$/$mm oC$,$ T$($am$($B$)=20$ oC