Energy stores and transfers
Energy is stored in kinetic, gravitational potential, elastic potential, thermal, chemical, nuclear and electrostatic stores. It is transferred by heating, mechanically, electrically or by radiation. Energy cannot be created or destroyed.
- Ek = ½ mv²
- Ep = mgh
- Ee = ½ ke²
- ΔE = mcΔθ
Power, efficiency and insulation
Power is the rate of energy transfer: P = E/t. Efficiency = useful output / total input. Wasted energy usually heats the surroundings. Insulation, double glazing and thicker walls reduce thermal transfer by conduction, convection and radiation.
Energy resources
Renewable resources include wind, solar, hydroelectric, geothermal, tidal and bio-fuel. Non-renewable include coal, oil, gas and nuclear. Compare reliability, environmental impact and availability in exam answers.
Download Energy slides (PowerPoint)
Taught with support from Joseph Danso, Science Lecturer in London. Book a session.