Question

A copper rod and an aluminum rod of the same length and cross-sectional area are attached end to end (Fig. 14-15). The copper endis placed in a furnace which is maintained at a constant temperature of242°C. The aluminum end is placed in an ice bath held at constant temperature of 0.0°C.Calculate the temperature at the point where the two rods are joined.
°C

Figure 14-15

Answer 1

172

Answer 2

Q/t = kA(Tf-Ti)/L

This represent the power transmitted by the heat as it is transferred through the rod. Since the two rods are connected, the two will transmit an equalamount of power:

(Q/t) of aluminum = (Q/t) of Copper
(237)(A)(Tf - 0)/L = (401)(A)(Tf - 242)/L
237(Tf) = 401(242 - Tf)
237Tf = 401(242) - 401Tf
Tf = (401)(242)/(237+401)
Tf = 152.103 degrees celsius

BOL