the temperature as a function of position and time in the bar, i.c., do not solve the differential equation just show maintained in contact with a heat sink at its lower surface, and initially the temperature throughout the bar is A long copper bar of rectangular cross sectior, whose width W is much greater than its thickneas L, is approximately equal to that of the sink, To Suddenly, an electric current is passed through the bar and an air To. Obtain the differential equation and the boundary and initial conditions that could be solved to determine stream of temperature T is passed over the top susface, while the bottom surface continues to be maintained at it. Assume the problem can be modeled as one-dimersional in X. To Heat Sink