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KEEPING THINGS WARM OR COOL
Some materials are better insulators than others. This means they will keep things warm or cool depending on their original state. Which, out of these materials do you think is the best insulator?
Cotton wool
Newspaper
Tin foil
Fabric |
Write down your answer.
Now carry out these two experiments to see if your answer is correct.
KEEPING THINGS COOL
You will need five ice cubes and a piece of cotton wool, a sheet of newspaper , a sheet of tin foil, a piece of fabric and some paper towels. Your task is to find out which one will be the best at keeping the 'Ice Cube' cool i.e., slow down the rate of melting.
Wrap four equally sized ice cubes up completely in each of the materials. Leave the fifth ice cube on the paper towel to melt to room temperature. This will act as a control. After half an hour, unwrap the ice cubes and see which one was the best at keeping the ice cube cool.
What happened to the others?
Were you right at the beginning? Discuss your findings with your class and teacher.
KEEPING THINGS WARM
You will need five plastic containers filled with warm water (say 40°c) and a piece of cotton wool, a sheet of newspaper, a sheet of tin foil, a piece of fabric and a thermometer. Your task is to find out which material will be the best at keeping the water warm.
First of all, record the water temperature of each container and wrap four of the containers up completely in the materials. Leave the fifth container alone to cool to room temperature. This will act as a control. After half an hour, unwrap each of the containers in turn and take the water temperature. Which one was the best at keeping the water warm?
What happened to the others?
Using graph paper, record your results of the hot water experiment.
Were you right at the beginning? Discuss your findings with your class and teacher.
Materials that keep warm things warm also keep cool things cool. They are known as insulators.
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