Physics - 2 Energy Transfer by Heating - Required Practical 2: Thermal Insulators

Aims:

  • to test the insulating capability of different materials

Risk Assessment:

  • electrical appliances can be dangerous if handled with moisture

  • hot water can burn

Safety:

  • dry hands before coming into contact with electrical appliances

  • be cautious with hot water and if you scald yourself, run under cold water and tell a teacher

Equipment:

  • 6 beakers

  • 6 thermometers

  • electric kettle (+ water)

  • 6 pieces of cardboard

  • scissors

  • stopwatch

  • different insulating materials/insulating material of different thicknesses/enough insulating material to layer

  • rubber bands

Control variables:

  • temperature of surroundings

  • volume of water in beaker

  • material covering top

  • size of beaker

  • temperature of water at beginning

Independent variable:

  • the material insulating the beaker

Dependent variable:

  • the rate that the water cools at

Method:

  1. Set up 6 beakers, each with a different material wrapped around them

  2. Pour 200cmÂł of hot water into each beaker

  3. Place a piece of cardboard on each beaker as a lid

  4. Push a thermometer through the cardboard lid so that the bulb is in the water

    (Note: you may need 6 people for this experiment, or you do it beaker by beaker. If you’re alone, you must start each beaker with water of the same temperature)

  5. Record the starting temperature of the water, and start the stopwatch

  6. For 20 minutes in total, record the temperature of the water in each beaker every 5 minutes

  7. Plot a graph of temperature against time for each material to get 6 cooling curves