S3.8.6 For the adult
Keeping warm and cool
How can I keep my tea warm for longer?
What this chapter teaches
Insulators trap still air, so heat leaves slowly. A fair test changes one thing only. A wet clay pot cools its water because evaporation takes energy from the pot, and it works best in dry, moving air.
Three questions to ask
There is no one right wording. Listen for the idea.
- Why does a woollen cloth keep a cup of tea warm?
- What must stay the same in a fair test of three wraps?
- Why does a clay pot cool water better on a dry day than a humid day?
After the chapter, the learner can
- Test which material keeps hot water warm longest
- Explain how a wet clay pot keeps water cool
What they copy into their notebook
Insulators trap still air and slow heat down. A fair test changes one thing. A wet clay pot cools water as water evaporates and takes energy away, best in dry air.