insulation & lubricant

• What is the main focus of today's video?

  Reducing unwanted energy transfers
• What are the two methods discussed for reducing energy loss?

  Thermal insulation and lubrication
• Why is it important to understand principles rather than memorize details?

  To suggest energy loss reductions in exams
• What do most people prefer for their homes regarding temperature?

  Warm even in cold weather
• What is the goal of reducing heat energy loss in homes?

  To keep the house warm
• What is convection in terms of heat transfer?

  Heat transfer through liquids and gases
• How do foam seals help in energy conservation?

  They prevent air from escaping
• What is conduction in terms of heat loss?

  Heat lost directly through solids
• What type of walls do houses typically have to reduce heat loss?

  Thick walls with low thermal conductivity
• What are cavity walls?

  Two layers of bricks with an air gap
• Why is air a poor conductor of heat?

  It does not transfer heat well
• What is the issue with having an air gap in cavity walls?

  It allows convection to occur
• How is insulating foam used in cavity walls?

  It fills the gap with air bubbles
• What is the difference between single and double glazing?

  Single has one pane, double has two
• How does double glazing reduce heat loss?

  It reduces conduction across the air gap
• What is friction in terms of energy transfer?

  Resistance when moving over a solid
• Why is reducing friction important?

  It increases efficiency of energy transfer
• How can oil help in reducing friction?

  By acting as a lubricant
• How does streamlining vehicles help with energy efficiency?

  It reduces air resistance friction
• What are the methods to reduce unwanted energy transfers?

  • Thermal insulation
  • Lubrication
• What adaptations do buildings have to reduce heat loss?

  • Sealed doors and windows
  • Thick walls with low thermal conductivity
  • Cavity walls with insulating foam
  • Double glazing
• What are the effects of friction on energy transfer?

  • Reduces efficiency
  • Causes heating of objects
• How does lubrication affect energy transfer in machines?

  • Reduces friction
  • Increases efficiency