167. In the figure, two rods each 50 cm long with equal cross-sections are connected together. When the thermal conductivity of aluminum is three times the thermal conductivity of iron, the temperature at the junction of the two rods is how many degrees Celsius? [Figure: Iron rod (50 cm) and Aluminum rod (50 cm) connected, with water at $100^\circ$C on the iron side and water at $20^\circ$C on the aluminum side] (1) $80$ (2) $40$ (3) $45$ (4) $30$ \hrule Calculation Space %% Page 28 Physics120APage 11
\textbf{167.} In the figure, two rods each 50 cm long with equal cross-sections are connected together. When the thermal conductivity of aluminum is three times the thermal conductivity of iron, the temperature at the junction of the two rods is how many degrees Celsius?
\textit{[Figure: Iron rod (50 cm) and Aluminum rod (50 cm) connected, with water at $100^\circ$C on the iron side and water at $20^\circ$C on the aluminum side]}
\hspace{1cm} (1) $80$ \\
\hspace{1cm} (2) $40$ \\
\hspace{1cm} (3) $45$ \\
\hspace{1cm} (4) $30$
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