Energy chains
Answers are for parents and teachers.
1
Draw the energy chain of a boiled egg for breakfast heated on a gas cooker, starting with the Sun.
Sun, ancient plants and animals, natural gas (chemical), flame (heat), water, egg cooks.
2
A fan takes in 40 units of electrical energy. It gives out 30 units of motion. The rest is sound and heat. How many units?
40 − 30 = 10 units.
3
Name one device at home and write its energy input, useful output and wasted output.
Answers differ, for example lamp: electrical; light; heat.
4
Explain to someone at home why a flat battery has not lost its energy for ever.
The energy changed into other forms such as light, sound and heat. It is conserved.
5
Write a claim: how can the Sun help us to get hot water? Use a solar water heater on a roof as evidence.
Answers differ. For example: Sunlight heats water in a solar heater, so sunlight can be turned into heat.