Which statement best describes heat flow direction when two objects are in contact and have different temperatures?

• A. Heat flows from the cooler object to the hotter object until they share the same temperature.
• B. Heat flows from the hotter object to the cooler object until they share the same temperature.
• C. Heat flow stops immediately after contact.
• D. Heat flows randomly.

Answer: (B)

Heat transfer is driven by a temperature difference, moving from the hotter object to the cooler one until both reach the same temperature. When two objects touch, energy flows from the object with higher average molecular kinetic energy to the cooler object, continuing until thermal equilibrium is reached. This is why the correct statement is that heat moves from hot to cold and only stops once the temperatures are equal. The idea that heat would flow from cold to hot, stop immediately, or move randomly doesn’t align with how temperature differences drive energy transfer.