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23 Cards in this Set
- Front
- Back
- 3rd side (hint)
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the greenhouse effect |
Short wavelength radiation like infrared and light enter the atmosphere But longer wavelength infrared emitted by the objects on earth so they can't escape |
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All objects emit this to varying degrees |
Infrared radiation |
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Matt surfaces vs smooth surfaces |
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Best emitter of radiation? |
Dark, matt surfaces |
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Worst emitter of radiation |
Light shiny surfaces |
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Two qualities of light shiny surfaces in comparison to dark matt surfaces |
They absorb less radiation They reflect more radiation |
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Properties used to describe states of matter? |
Flow Shape Volume Density |
There are 4 of them |
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Why are metals the best conductors |
Metals contain delocalised electrons. This means that when heated the electrons are free to diffuse and collide with other electrons and the positive ions in order to transfer kinetic energy (kinetic theory =heat) |
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What rises in a convection current |
The hot FLUID, not HEAT |
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Why does evaporation cool the liquid |
The faster moving molecules are leaving the liquid, thus lowering the average temperature |
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How to increase evaporation |
Increase the surface area of the liquid Increase the liquid's temperature |
There are 2 |
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Rate of energy transfer depends on? |
-Shape size and material of object -Materials that the object is in contact with -Temperature difference between object and its surroundings |
3 marks |
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What is specific heat capacity |
The amount of energy needed or transferred to raise the temperature of 1 kg of a substance by 1degree C |
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Specific heat capacity of water? |
4200 j/kg/C |
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How can energy transfer from homes be reduced |
-Loft insulation -Cavity wall insulation -Double glazing -Draught proofing -Aluminium foil behind radiators |
5 marks |
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What are U-values |
The energy per second that passes through one square metre of material when the temperature difference across it is 1C |
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The amount of mains electrical energy transferred to an appliance depends on what? |
How long it used for And The power supplied to it |
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What do each of these stand for in E = P x t |
E = energy transferred in Kwh P = the power in kW t= time taken for the energy to be transferred in hours |
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What is power? |
The rate of transfer of energy |
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What is the unit for power? |
Watts |
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What is the unit for energy? |
Joules |
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Describe watts in terms of joules |
Watts = joules per second |
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If we want to find the energy transferred in joules |
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