Required Practical 2: 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
• Repeating the experiment with insulating material

  1. Use an insulating material (e.g. bubble wrap) to fill the gap between the two beakers

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

  3. 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
• Investigating how thickness affects thermal insulation

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

  2. Measure the temperature every 3 minutes for 15 minutes

  3. Repeat the experiment with 2, 4, and 6 layers of newspaper around the beaker
• More layers of insulation


  Slower the water cools down
• More layers of insulation is a more effective thermal insulator than fewer layers