It is January and Haley, Sarah and Becky are tired of having cold feet while waiting for the school bus to come in the morning. They

all wore nylon socks, and thought that a material such as wool would be better at keeping their feet warm. They decided to design an

experiment to test the effectiveness of wool, cotton and nylon as insulators. They fill identical bottles with 200 ml of water at 100 C

and place inside each sock

What observation is being made?