Question

two metal blocks of different temperatures are put in contact with one another in a closed system. the top block is at ( t_{\text{top}} = 0^circ \text{c} ), and the bottom block is at ( t_{\text{bottom}} = 40^circ \text{c} ). top metal block diagram, bottom metal block 40°c. what will happen to the temperatures of the blocks after a long period of time? options: a. ( t_{\text{top}} = t_{\text{bottom}} ); b. ( t_{\text{top}} > t_{\text{bottom}} ); c. ( t_{\text{top}} = 0^circ \text{c}, t_{\text{bottom}} = 0^circ \text{c} ); d. ( t_{\text{top}} = 40^circ \text{c}, t_{\text{bottom}} = 40^circ \text{c} ).

Explanation:

In a closed system, when two objects at different temperatures are in contact, heat transfers from the hotter object (bottom block, 40°C) to the colder object (top block, 0°C) until thermal equilibrium is reached. At equilibrium, their temperatures become equal. Option A states \( T_{\text{top}} = T_{\text{bottom}} \), which aligns with the principle of thermal equilibrium. Option B is incorrect as heat flows from hot to cold, so top can't be hotter than bottom. Option C and D are incorrect because the final temperature will be between 0°C and 40°C (not necessarily 0 or 40), and equal for both blocks.

Answer:

A. \( T_{\text{top}} = T_{\text{bottom}} \)