$(20$ pts $)$ A composite block with uniform cross sectional area consists of a slib of aluminum with length $L_A=0\mathrm{.}375m$ and a slab of copper with length $L_C=0\mathrm{.}465m,$ as shown below. The temperatures of their outer surfuces are maintained at $T_A=0\mathrm{.}00C$ and $T_C=100\mathrm{.}0C.$ Assuming steady$-$state conditions $($which means the rate of heat transfer is constant throughout the composite block$),$ determine the temperature at the interface between the aluminum and copper slabs. Hint: Because the problem is at stendy state, you can write an expression for heat transfer rate $($heat current$)$ through the aluminum slab and an expression for heat transfer rate through the copper slab. Setting these expressions equal to one another will yield one equation for the unknown interiace temperature, $T_1.$ The thermal conductivity for aluminum is $k_A=238\frac{W}{m}*C$ and the thermal conductavity for copper is $k_C=397\frac{W}{m}*C.$