Calculating

• Power rating


  Tells us how many joules of energy are transferred every second
• Calculating total energy transferred

  Energy (J) = Power (W) x Time (s)
• Appliances


  • Kettle
  • Fan
  • Iron
  • Blender
• Kettle has a power rating of 2200 watts and is used for 80 seconds
• Fan has a power rating of 20 watts and is used for 1 hour
• Iron is used for 5 minutes and transfers 600,000 J of energy
• Blender has a power of 400 watts and transfers 48,000 J of energy