Energy - Coggle Diagram
1.1 Energy changes in a system
A system is a group of objects that pass energy between them, e.g. a pendulum swing includes the pivot and the swing, and transfers energy from gravitational potential to kinetic and back again.
A 600W toaster running for 2 minutes has an transfers 72kJ of energy, and a 400W toaster running for 3 minutes transfers the same amount of energy, but has a different power output.
1.2 Conservation and dissipation of energy
Energy can be stored and transferred, but cannot be destroyed or created.
The correlation between thermal conductivity and the rate of energy transfer is positive- the more conductive something is, the faster it will transfer energy.
Efficiency=useful power output/total power input
Efficiency=useful energy output/total energy input
1.3 National and global energy resources
A renewable energy resource is an energy resource that can be replaced as fast as it is used up..
Non-renewable energy resources include: Fossil fuels (coal, oil, natural gas), Nuclear, Biomass (if it is not replenished)
Renewable energy resources include: Solar, Wind, Wave, Tidal, HEP, Geothermal, Biomass (if it is replenished).
Nuclear energy is more reliable than wind or solar because it generates electricity all of the time, whereas the sun isn't always shining and the wind isn't always blowing.
Some energy resources, such as coal, are used in factories as it is more efficient and cheaper than some other renewable resources, but solar power is used to power homes, as they are better for the environment.