Question

two solid blocks are heated to the temperatures shown. the blocks are placed so they touch. which diagram shows the direction heat will flow?

Explanation:

Step1: Recall heat - flow principle

Heat always flows from a region of higher temperature to a region of lower temperature.

Step2: Identify temperature regions

One block is at 19°C and the other is at 0°C.

Step3: Determine heat - flow direction

Heat will flow from the 19°C block to the 0°C block.

Answer:

The diagram where the arrow points from the 19°C part to the 0°C part shows the correct direction of heat flow.