efficiency

• calc for efficiency

  useful output / total input
• how can efficiency of a system be increased?

  • reducing waste output - lubrication, thermal insulation
  • recycling waste output
• how would lubrication affect the efficiency of a machine

  • less friction
  • less energy wasted
  • increased efficiency
• why are energy efficient devices good?

  • waste less energy
  • minimise environmental impact from electricity generation