Question

A stick is a connection of two same -diameter metal rod 5 cm , and a length of both stick is 0,6m. The thermal conductivity of the first rod 92 cal /s.m.°C ,

and the second stick 50 cal / s.m.°C . The temperature at the free end of the first rod
100 °C and the free end of the second rod 0 °C , the temperature is kept constant .
Determine heat transfer within 5 minutes .

Answer 1

First find temp at the join. Since Q must be the same k1 A deltaT t/L = k2 A deltaT t/L. A, L and t are the same so k1 (100-T) =k2 (T-0) and T is about 65C. Now go back and use Q =kA deltaT t/L