A 12-cm-long bar with a square cross section, as shown in Fig. P17133, consists of a 1-cm-thick

Question:

A 12-cm-long bar with a square cross section, as shown in Fig. P17–133, consists of a 1-cm-thick copper layer (k = 380 W/m⋅K) and a 1-cm-thick epoxy composite layer (k = 0.4 W/m⋅K). Calculate the rate of heat transfer under a thermal driving force of 50° C when the direction of steady one-dimensional heat transfer is (a) from front to back (i.e., along its length), (b) from left to right, and (c) from top to bottom.