# physics init 1 energy

what is the law of conservation of energy?
energy cannot be created or destroyed. it can be transfered, stored or dissipated
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define dissipation
energy being transfered to the surroundings
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describe how thermal conductivity of a material affects how it transfers energy by conduction
if a material has a high thermal conductivity , it will transfer heat via conduction at a much quicker rate
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how is energy lost from a building? what factors affect this?
energy is transfered to thermal energy stores of the surroundings. the factors that affect this are the thermal conductivity of the walls and the thickness of them.
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what is the equation linking efficiency, useful output energy transfer and total input energy transfer?
effficiency = useful output energy (divided by) total imput energy transfer
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what is the equation linking efficiency, useful power output and total power input?
efficiency = useful power output (dividied by) total power output
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when energy is transfered in a closed system, what happens to the total amount of energy?
total energy does not change
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how can the efficiency of an enrgy transfer be increaced?
by increacing the useful output by reducing the wasted energy
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why is a streamlined vehicle more effecient than one which is not streamlined?
it wastes less energy due to air resistance ans so has a higher useful output energy
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list the main energy reasorces
fossil fuels, nuclear fuel, biofuel, wind, hydroelectricity, geothermal, tidal, waves, solar
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define renewable energy resources
a resource which can be replenished
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define non-renewable energy resources
a resource that will eventualy run out
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## Other cards in this set

### Card 2

#### Front

define dissipation

#### Back

energy being transfered to the surroundings

### Card 3

#### Front

describe how thermal conductivity of a material affects how it transfers energy by conduction

### Card 4

#### Front

how is energy lost from a building? what factors affect this?

### Card 5

#### Front

what is the equation linking efficiency, useful output energy transfer and total input energy transfer?