Question

85°c block 1, 93°c block 2. later, the temperature of each block is measured again. which pair of temperatures is possible? options: 90°c block1 98°c block2; 87°c block1 91°c block2; 85°c block1 89°c block2; 90°c block1 88°c block2

Explanation:

Step1: Analyze heat transfer logic

When two objects (blocks) are in contact, heat flows from the hotter to the colder until thermal equilibrium (or closer). Initial temps: Block 1 = \(85^\circ\text{C}\), Block 2 = \(93^\circ\text{C}\). So Block 2 (hotter) should cool down, Block 1 (colder) should warm up. Final temps: Block 1 > \(85^\circ\text{C}\), Block 2 < \(93^\circ\text{C}\), and Block 1’s temp < Block 2’s temp (or equal, but here initial Block 2 is hotter, so final Block 2 should still be ≥ Block 1, or close).

Step2: Evaluate each option

• Option 1: \(90^\circ\text{C}\) (Block1), \(98^\circ\text{C}\) (Block2). Block2 got hotter (from \(93\) to \(98\)) – impossible (should cool).
• Option 2: \(87^\circ\text{C}\) (Block1, >85), \(91^\circ\text{C}\) (Block2, <93). Both trends correct (Block1 warms, Block2 cools), and \(87 < 91\) (thermal logic holds).
• Option 3: \(85^\circ\text{C}\) (Block1, no warming) – impossible (should warm from 85).
• Option 4: \(90^\circ\text{C}\) (Block1), \(88^\circ\text{C}\) (Block2). Now Block1 (\(90\)) > Block2 (\(88\)) – but initial Block2 was hotter (\(93 > 85\)). Heat flows from hot to cold, so Block2 can’t end up colder than Block1 (unless time is infinite, but this is a “later” measurement, not equilibrium yet; Block2 should still be at least as hot or closer, not colder). So invalid.

Answer:

The possible pair is \(87^\circ\text{C}\) (Block 1) and \(91^\circ\text{C}\) (Block 2) (the second option in the grid).