Plastic foam Graphite Calcium Copper
It is thick and fatty It is fine and dry It traps a layer of air It lets air circulate easily
It reduces heat loss by radiation Thicker glass puts heat back into the house Two layers of glass puts heat back into the house It traps a layer of air
efficiency = useful energy out x total energy in efficiency = useful energy out + total energy in x 100 efficiency = total energy in ÷ 100 efficiency = (useful energy out ÷ total energy in) x 100
Light Sound Heat Electricity
Plant energy Animal energy Electrical energy Chemical energy
Heat Sound Gas and liquid Heat and light