9I Summary Sheets
9
Energy and electricity
Nothing would happen without energy. Energy is needed to:
I
· keep our bodies working
· make machines work
· heat homes, schools and offices.
Energies in action
· heat energy
· light energy
· sound energy
· electrical energy
· kinetic (movement)…
Page 2
9I Summary Sheets (continued)
9
Energy cannot be made or destroyed, but can only be changed from one form to I
another. This is the law of conservation of energy.
Voltage
A circuit must have a cell or power supply to provide a voltage. The voltage pushes
the electrons around…
Page 3
9I Summary Sheets (continued)
9
I Electricity can be generated from renewable resources such as wind and moving
water. These will become more important as fossil fuels run out.
Sometimes we need a source of portable electricity when we are not close to the
mains. This can be supplied by…
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