Designing an insulated container
Chemistry · Key Stage 2 · The School
The design challenge
Here is the task. Keep a cup of hot water warm for twenty minutes. Use only the materials you are given. This is not just about one material. It is a design task. It uses what you learned about heat conductors and insulators.
Choosing materials
A poor conductor makes a good insulator. It slows heat escaping. Wool is a poor conductor, so it helps. So do bubble wrap, foam and paper. Bare metal is a good conductor, so it performs worse. A single thin layer also performs worse, because heat can escape around it.
Testing fairly
Every group must start the same way. Same amount of water. Same starting temperature. Same size of cup. Measure after exactly twenty minutes. Otherwise a good design could look bad. It might have simply started with cooler water.
Learning from the first attempt
One cup was wrapped in wool. It lost less heat than a bare cup. But a gap was left at the top. Heat escaped through the gap as steam. The gap was sealed on a second try. That kept several more degrees. The redesign, not just the wool, made the difference. A good design is often improved this way, one small fix at a time.