Two metal rods, one silver and the other gold, are attached to each other. The free end of the silver rod is connected to a steam chamber, with a temperature of 100°C, and the free end of the gold rod to an ice water bath, with a temperature of 0°C. The rods are 5.0 cm long and have a square cross-section, 2.0 cm on a side. How much heat flows through the two rods in 60 s? The thermal conductivity of silver is 417 W/(m·K), and that of gold is 291 W/(m·K). No heat is exchanged between the rods and the surroundings, except at the ends.

Question

Quizplus · Accepted Answer

The heat flow through the rods can be calculated using the formula for thermal conduction: $ Q = \frac{k \cdot A \cdot \Delta T \cdot t}{L} $. For two rods in series, the equivalent thermal conductivity $ k_{eq} $ is given by $ \frac{1}{k_{eq}} = \frac{1}{k_{1}} + \frac{1}{k_{2}} $. Using the given values, the heat flow is approximately 8.2 kJ.

Two Metal Rods, One Silver and the Other Gold, Are