general

• conservation of energy - energy cannot be created or destroyed, only transferred
• gravitational potential - energy stored in an object due to its position in a gravitational field
• thermal energy - energy due to heat
• power - rate of energy transfer
• work done - the energy transferred when a force acts over a distance
• efficiency - the ratio of useful output energy transfer to total energy input
• non-renewable energy sources include gas, oil, coal and nuclear power.
• burning fossil fuels results in the emission of greenhouse gases which contribute to global warming
• nuclear power plants do not release CO2 but produce radioactive waves which must be contained
• reducing energy waste= lubrication (oil in a motor reduces friction so less energy is lost through friction)
• thermal insulation - double glazing ; less useful thermal energy lost
• The higher the thermal conductivity of a material, heat is allowed to travel through the material more easily, so the higher the rate of energy transfer by conduction across the material.
• geothermal energy uses hot rocks inside the earth to produce steam and drive a turbine
• 3 disadvantages of nuclear power:

  nuclear fuel is a finite resource, produces radioactive waste which is harmful and lasts a long time, it is expensive and there is a risk of a nuclear meltdown/accident