power ashfield direct learning kirsten lounds. ks4 energy
TRANSCRIPT
Power
Ashfield Direct Learning
Kirsten Lounds.
Ks4 Energy
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
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.
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