energy Flashcards

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1
Q

name the different energy stores

A
  • thermal
  • kinetic
  • gravitational potential
  • elastic
  • magnetic
  • chemical
  • nuclear
  • electrostatic
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2
Q

what are the different ways energy can be transferred by

A
  • mechanically
  • heating
  • electrically
  • light
  • radiation
  • sound
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3
Q

what is a system

A

a collection of matter

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4
Q

what is kinetic energy

A

the energy an object possesses due to its motion

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5
Q

what does kinetic energy depend on

A

speed and mass

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6
Q

how do you calculate kinetic energy

A

kinetic energy = 1/2 x mass x speed^2

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7
Q

what does the gravity experienced by two objects depend on

A

mass and how far apart those objects are

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8
Q

how do you calculate weight

A

weight = mass x gravitational field strength

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9
Q

what is gravitational potential energy

A

energy or work require to lift up an object against gravity

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10
Q

what is the formula for gravitational potential energy

A

gravitational potential energy = mass x gravitational field strength x height

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11
Q

what is internal energy

A

the total energy stored by the particles making up a substance or system
(also the amount of energy released as that substance cools down)

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12
Q

what is specific heat capacity

A

the amount of energy needed to raise the temperature of 1kg of a substance by 1 degree celsius

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13
Q

what is the equation for the change in internal energy

A

change in internal energy = mass x specific heat capacity x temperature change

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14
Q

what is the conservation of energy principle

A

energy can be transferred usefully, stored or dissipated, but can never be created or destroyed

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15
Q

what are the 3 different ways heat can be transferred and by what medium

A

conduction for solids
convection for liquids
radiation for empty space

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16
Q

what is conduction

A

when vibrating particles transfer energy to neighbouring particles

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17
Q

what is thermal conductivity

A

how well objects transfer energy by conduction

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18
Q

what is convection

A

when heated particles with more energy move up while colder particles move down to create a convection current

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19
Q

what is radiation

A

when heat to transferred through infrared waves

20
Q

how can you reduce the amount of heat energy loss

A

thermal insulation and lubrication

21
Q

what is friction

A

the resistance that an object encounters when moving over a solid, or moving through a liquid

22
Q

what is power

A

the rate at which energy is transferred or the rate at which work is done

23
Q

what is power measured in

A

watts (W)

24
Q

what is efficiency

A

proportion of energy supplied that is actually transferred into useful energy

25
Q

give examples of non-renewable energy

A
  • natural gas
  • coal
  • oil
  • nuclear
26
Q

what is the difference between non-renewable and renewable energy sources

A

non-renewable energy sources cannot be replenished at the same rate they are being used and will therefore eventually run out.
renewable energy sources can be replenished at the same or faster rate that they are being used and will therefore not run out.

27
Q

how does wind power work

A

wind is captured through turbines and turn a generator which turns kinetic energy into electric energy

28
Q

how does solar power work

A

generated by solar cells which generate electric currents directly from sunlight

29
Q

what are the pros of wind and solar energy

A
  • low running cost
  • doesn’t damage the environment
  • renewable
30
Q

what are the cons of wind and solar energy

A
  • high upfront cost
  • making them does produce pollutants
  • dependent on the weather
  • no way to increase supply
  • take up lots of space
31
Q

what is geothermal energy

A

thermal energy generated and stored in the earth’s crust

32
Q

how can geothermal energy be used for heating

A

water is pumped down into the earth’s curst to heat up and then returns back to heat our homes

33
Q

how can we generate electricity using geothermal energy

A

water left until it is converted into steam, as the steam rises it turns turbines which then generate electricity

34
Q

what are the pros of geothermal energy

A
  • installing only damages the environment slightly
  • running it doesn’t produce any pollutants
  • reliable
35
Q

what are the cons of geothermal energy

A
  • power plants can be expensive to build

- only use this source in certain areas

36
Q

what is biofuel

A

fuel thats made from recently living organisms

37
Q

where do biofuels usually come from

A
  • plants
  • algae
  • animal waste
38
Q

why are carbon fuels considered carbon neutral

A

even though they release carbon dioxide, that carbon dioxide was once taken up from the atmosphere anyways

39
Q

what are the pros of biofuels

A
  • cheap to make
  • easy to transport
  • can mix them with fossil fuels
40
Q

what are the cons of biofuels

A
  • need somewhere to grow all these plants which will damage the environment
  • all the processing will require energy and release more carbon dioxide
41
Q

what is a hydroelectric dam

A

trapping water that has come from upstream to create a reservoir

42
Q

what is a tidal barrages

A

making use of tides, during high tight water is wrapped creating a difference in water level

43
Q

how do hydroelectric dams and tidal barrages create energy

A

the difference in water levels means the stored water has a huge amount of gpe which can be converted into electricity through generators

44
Q

what are the pros of hydroelectric dams and tidal barrages

A
  • large amount of energy with no pollution
  • reliable source of electricity
  • running costs are fairly low
  • work on both large and small scales
45
Q

what are the cons of hydroelectric dams and tidal barrages

A
  • sometimes stops boats and fishes from travelling
  • risk of flood
  • big impact on the surroundings