thermal insulators

• Thermal insulator

  A material that reduces the flow of heat
• Investigating the effectiveness of thermal insulators

  1. Place a small beaker inside a larger beaker

  2. Use a kettle to boil water

  3. Transfer 80 cm^3 of hot water into the small beaker

  4. Use a piece of cardboard as a lid for the large beaker with a hole for a thermometer

  5. Place the thermometer through the hole with the bulb in the hot water

  6. Record the starting temperature and start a stopwatch

  7. Record the temperature every 3 minutes for 15 minutes

  8. Repeat the experiment using an insulating material (e.g. bubble wrap) between the beakers

  9. Test a range of insulating materials (e.g. cotton wool, polystyrene balls)

  10. Use the same mass of insulating material in each case
• Independent variable

  The variable that is changed in the experiment
• Dependent variable


  The variable that is measured for each change in the independent variable
• Control variables

  Variables that are kept constant in the experiment
• The water will cool down most slowly with the most effective insulating material
• Investigating how the thickness of a material affects thermal insulation

  1. Start with a beaker containing 80 cm^3 of hot water

  2. Measure the temperature of the water every 3 minutes for 15 minutes

  3. Repeat the experiment with 2 layers of newspaper around the beaker

  4. Repeat the experiment with 4 layers and 6 layers of newspaper
• Independent variable

  The number of layers of newspaper
• Dependent variable

  The temperature of the water
• The more layers of newspaper, the slower the water cools down, because more layers is a more effective thermal insulator