Question

A solid slab of metal at room temperature sits on a lab bench as shown below. Using a heating device, an engineering student quickly raises the left surface temperature to T1. As a result of the heating process, the right surface temperature quickly increases to T2. Both of these temperatures are higher than room temperature and neither changes while heat continues to be applied to the left surface of the slab. The temperature variation is observed as shown in the diagram below. If the linear temperature profile remains constant while the student continues to apply heat to the slab, we can say that:

A. The slab is at steady-state but is not in thermal equilibrium with the air in the room
B. The slab is not at steady-state but is in thermal equilibrium with the air in the room
C. The slab is not a steady-state and is not in thermal equilibrium with the air in the room
D. The slab is at steady-state and is in the thermal equilibrium with the air in the room

Answer 1

The heated metal slab is in a steady-state because the temperature profile does not change over time. However, it's not in thermal equilibrium with the air in the room, as its temperature differs from the room temperature.

Step-by-step explanation:

If a solid slab of metal is quickly heated on one side to a temperature T1 and the other side of the slab reaches a temperature T2, where both temperatures are above room temperature and remain constant as heat continues to be applied, the slab is said to be in a steady-state condition. This is because the temperature profile across the slab does not change over time, indicating a consistent rate of heat transfer throughout the material. However, since the slab is at a higher temperature than the air in the room (assuming room temperature is not equal to either T1 or T2), it is not in thermal equilibrium with its environment. The slab will continue to exchange heat with the surrounding air until thermal equilibrium is reached. Therefore, the correct answer is 'A. The slab is at steady-state but is not in thermal equilibrium with the air in the room.'