energy and particle model Flashcards
what is lubrication
way of reducing unwanted energy transfer due to friction
what is streamlining
way of reducing energy wasted due to air resistance or drag in water
what is thermal conductivity
how quickly energy is transmitted through it
what affects thermal conductivity in a building
- thickness of walls/ roof
- thermal conductivity of its walls/ roof
what does the energy transfer per second through a material depend on
- materials thermal conductivity
- temperature difference between the two sides
- thickness of the material
whats specific heat capacity
amount of energy required to raise 1kg of a substance by 1°c
what is specific latent heat
amount of energy required to change the state of 1kg of material
what is specific latent heat of fusion
amount of energy required to melt 1kg of a material with no change in temperature
specific latent heat of vaporization
amount of energy required to evaporate a substance with no change in temperature
does a higher temp mean more or less infrared radiation absorbed
more
what’s equal to the amount of infrared radiation at constant temp
amount of infrared emitted
what does the sun emit towards the earth
radiation
what does the earth do with radiation
- some emitted back into space
- some (longer) wavelengths absorbed by greenhouse gases
- some greenhouse gases re-emit radiation
what are the non renewable fuels (4)
- coal
- oil
- gas
- nuclear fission
what are the renewable fuels (7)
- tidal
- solar
- geothermal
- wind
- hydroelectric
- wave
- biofuels
what does the blue wire in a plug do
neutral wire - completes circuit
what does the yellow/ green wire in a plug do
earth wire - safety feature - prevents casing becoming live
what does the brown wire in a plug do
live wire - provides current
what’s the journey in the national grid
power stations -> step up transformer -> (cables) -> step down transformer -> consumer
what does a step up transformer do
increases potential difference
which decreases current
which reduces amount of energy transferred to surroundings
what is charge (in terms of electrons)
when electrons are added or removed from an atom
what is static charge
insulating materials become charged when rubbed with other insulating materials
because electrons are transferred
what are electric fields
an area around a charger object
when two charged objects are close an electrostatic force is felt
what is a spark
when two objects have very strong electric fields between them, electrons in the air molecules with mllll be strongly attracted towards the positively charged objects (if strong enough) electrons pulled -> flow = spark
what is internal energy
sum of total kinetic and potential energy
order of scientists who discovered models and what they discovered
john dalton - solid sphere
jj thompson - plum pudding model
ernst rutherford - (alpha scattering), nuclear model (proton
niels bohr - nuclear model but electrons orbit in shells/ fixed distances
james chadwick - neutron
