Heat Transfer: Track Hot and Cold
Understand that heat is energy flowing from a hotter object to a colder one until both reach the same temperature, and that the final temperature is a weighted average based on mass and specific heat capacity.
Before you try
What if you touched a big cold block to a small hot one? Would they meet in the middle?
Try it out
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What happened?
Move a control to see what changes and why.
Only the two blocks exchange energy, with nothing lost to the room. Real objects always leak heat to their surroundings.
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Try these ideas
- Put 1 kg of hot iron against 1 kg of cold water. Which one moves further?
- Make block A ten times heavier than block B and predict the final temperature.
- Turn off the insulation and watch both blocks drift toward room temperature.
Why it works
Temperature tells you how hot something is. Heat is something different: it is energy on the move, and it only ever flows from the hotter object to the colder one. Nothing called "cold" travels the other way. The flow keeps going, getting slower as the gap narrows, until both objects sit at the same temperature, which is called thermal equilibrium.
Where they meet depends on more than temperature. Every material needs a certain amount of energy to warm each kilogram by one degree, its specific heat capacity, and water needs far more than metal. In this simulator you choose two materials, masses and starting temperatures, then watch the temperatures curve toward each other. Heat flow is modelled as a simple rate proportional to the temperature difference.
Check your understanding
Question 1 of 4
A hot block touches a cold block. What actually moves between them?
1 kg of water at 20 °C touches 1 kg of iron at 100 °C. Where does the final temperature end up?
When do the two blocks stop exchanging heat?
Is temperature the same thing as heat?
Explain it in your own words
What changed? Why did it happen? Where might you notice this in everyday life?
For parents & teachers
- Ask why a metal spoon feels colder than a wooden one at the same room temperature.
- Mix hot and cold water in measured amounts and check the final temperature.
- Discuss why a flask keeps drinks hot and cold equally well.