1. Power Ashfield Direct Learning Kirsten Lounds. Ks4 Energy

2. Calculating Power.  If we know the energy transferred and time, we can calculate the power rating or energy consumed per second  To help with this you can rearrange the formula.  A simple formula triangle will help. E P T

4. Power Ratings of Domestic Appliances.  All electrical appliances have a power rating  This tells you how much energy is transferred by the appliance every second. Power rating (W) 900W Power Rating (kW) 0.9Kw Energy Transferred (J/s) 900J/s  The greater the power rating, the more energy is transferred.

5. Working Out Power Ratings Of Domestic Appliances.  A toaster transfers 108,000J of energy in the 120secs it takes to toast bread.  P=E/T  P=108, 000J/120secs  P=900J/s 900W or 0.9kW Power rating (W) 900W Power Rating (kW) 0.9kW Energy Transferred (J/s) 900J/s