A thin flat plate of length $L$, thickness $t$, and width $W \geqslant L$ is thermally joined to two large heat sinks that are maintained at a temperature $T_{o}$. The bottom of the plate is well insulated, while the net heat flux to the top surface of the plate is known to have a uniform value of $q_{o}^{\prime \prime}$
(a) Derive the differential equation that determines the steady-state temperature distribution $T(x)$ in the plate.
(b) Solve the foregoing equation for the temperature distribution, and obtain an expression for the rate of heat transfer from the plate to the heat sinks.