1. Children Challenging Industry
What is the best material to keep a hot drink hot and a cold drink cold?
Children Challenging Industry

2. Dear Scientists,
At our drinks company, we are developing a new type of cup that will give our customers complete satisfaction. The cup will go on sale later this year; it will keep hot drinks hot and cold drinks cold.
We would like you to help us with our investigations by informing us which material we should use to make our cup.
Our tests so far have shown that three materials in particular are very good thermal insulators but we are unsure about the best way to test this. We have enclosed samples of these materials for you to examine:
metal
polystyrene
expanded polystyrene
We have heard of your reputation as being excellent investigators and we look forward to hearing from you soon with your ideas and recommendations.
Yours faithfully
I M THIRSTY
Development Manager

5. Which material kept the water the warmest?
Why?
Which material kept the water the coldest?
Why?