Energy resources

- Kinetic
- Thermal
- Chemical
- Gravitational Potential
- Elastic Potential
- Electrostatic
- Magnetic
- Nuclear

- Mechanically (force acting on it)
- Electrically (A charge moving through a p.d.)
- By Heating
- By Radiation (light/sound waves)

- Energy can be stored, transferred between stores, and dissipated
- Energy can never be created or destroyed

- Efficiency = (useful energy output / total energy input) x 100%
- Efficiency can never be equal or higher than 100%

- Radiation (infrared) occurs in s,l and gas
- Conduction (solids)
- Convection (liquids and gasses)

- Infrared Radiation
- Matte/Black - good absorbers and emitters of radiation
- Shiny/white - poor absorbers and emitters or radiation
- Hot object emits more radiation cooler objects absorbb more radiation

- Mainly in Solids
- Vibrating particles transfer kinetic energy to neighbouring particles
- This causes a rise in temperature

- Liquid and Gases only
- fluid heated- particles expand,move apart - become less dense- rise up - Denser/colder particles fall down to take its place. (water boilers)
Convectin occurs when the more energetic particles move from the hotter region to the colder, transferring energy

Conduction: attach beads to metal bar at regular intervals with wax, clamp it, heat one end of the bar, energy transfers and wax melts
Cnvection: purple potassium permaganate crystals in beaker of cold water, heat one side of the beaker

Fill leslie cube with boiled water, wait for it to warm up, measure temp from 4 sides - same tem. Measure IR with infrared detector. Repeat. More IR detected from black and matt than white and shiny

- How well an object transfers energy by conduction
- High thermal conductivity = quick transfer energy between particles
- Low thermal conductivity = reduced unwanted energy transfers

insulation, double glazing of windows
foam cavity wall insulation
reduce convection: stop fluid from moving, (insulation-clothess, blankets). reduce thermall radiation energy transfer use shiny and white object - poor emitter

Work Done = Energy Transferred
when a force moves an object through a distance work is done on the objcect and energy is transferred

Work Done = Force x Distance moved
W = F x d

- The rate at which energy is tranferred
1 W = 1 J of energy per second
Power = Work done / Time taken
P = Wd / t

- Kinetic Energy = 1/2 x mass x ( speed ) ²
- KE = 1/2 x m x v²

- Gravitational Potential Energy = mass x gravitational field strength x height
- GPE = m x g x h

when something falls energy from gravitational potentiol store is transferred to kinetic energy store.
Energy lost from GPE store = energy gained in the KE store