Reducing Unwanted Energy Transpers and Improving Efficiency

• How can you reduce unwanted energy transfers in a machine with moving, touching components?

  Lubrication
• True or false? A higher thermal conductivity means there is a high rate of energy transfer

  True
• Give four ways to prevent unwanted energy transfers in a home

  Soft insulation,

  Double-Glazed windows,

  Draught Excluders,

  Cavity walls
• True or False? Thicker walls make a house cool down quicker

  False
• What is the efficiency of an energy transfer? give the equation that relates efficiency to power

  How much energy is wasted. e.g The less energy that is wasted, the more efficiency the device is.

  Equation:

  Efficiency = Useful power output

  ————————————

  Total Power Input