Question

two identical blocks are heated to different temperatures. the blocks are placed so that they touch, and heat begins to flow between the blocks. the pair of blocks is insulated, so no energy escapes. later, the temperature of each block is measured again. which pair of temperatures is possible?

Explanation:

Step1: Understand heat - transfer principle

Heat flows from a hotter object to a colder object until thermal equilibrium is reached. The initial temperatures of the blocks are 23°C and 142°C. Block 1 is colder and Block 2 is hotter, so heat will flow from Block 2 to Block 1. The temperature of Block 1 should increase and the temperature of Block 2 should decrease.

Step2: Analyze each option

• Option 1: Block 1's temperature increased from 23°C to 35°C and Block 2's temperature decreased from 142°C to 130°C. This is consistent with heat - transfer.
• Option 2: Block 1's temperature decreased from 23°C to 4°C and Block 2's temperature increased from 142°C to 161°C. This is against the heat - transfer principle.
• Option 3: Block 1's temperature decreased from 23°C to 0°C and Block 2's temperature increased from 142°C to 165°C. This is against the heat - transfer principle.

Answer:

The pair of temperatures in the first option (35°C for Block 1 and 130°C for Block 2) is possible.