Energy Transfers

• Lubrication


  Reduces frictional forces
• Lubrication


  Lubricants flow easily between objects and coat them
• Streamlining reduces air resistance
• Insulation


  Reduces the rate of energy transfer by heating
• Thick walls with low thermal conductivity


  • Slower rate of energy transfer (building cools more slowly)
• Thermal insulation


  • Cavity walls with air gap
  • Loft insulation with fibreglass wool
  • Double-glazed windows with air gap
• Draught excluders


  • Reduce energy transfers by convection
• Reducing the difference between the temperature inside and outside the house will also reduce the rate of energy transfer
• Investigating effectiveness of different insulators


  1. Boil water

  2. Measure initial temperature

  3. Seal container for 5 minutes

  4. Measure final temperature

  5. Repeat with different insulating materials
• Factors affecting how good a material is at insulating


  • Thickness of insulating layer
  • Thicker insulating layer = less energy transferred and smaller temperature change