Pass Check: Energy
Energy is transferred between stores; total energy is always conserved.
Conservation of energy
Energy cannot be created or destroyed, only transferred between stores.
Efficiency
The proportion of input energy usefully transferred, expressed as a fraction or percentage.
Power
The rate at which energy is transferred or work is done, measured in watts.
Specific heat capacity
The energy needed to raise the temperature of 1 kg of a substance by 1°C.
Quick check
Mixed quiz
1. Which statement about energy security is correct?
2. Which energy resource has the highest reliability?
3. Why does insulation with a low thermal conductivity work well?
4. What is the unit of power?
5. Which describes a Sankey diagram?
6. Complete the sentence: Solar panels convert light to ______.
7. Which is an advantage of solar panels?
8. Calculate the efficiency of a motor producing 240 J useful from 800 J input.