Energy Flashcards

(81 cards)

1
Q

What are the units for energy

A

Joules (J)

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2
Q

What happens to used energy?

A

It is dissipated

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3
Q

What are the 8 different energy stores?

A
  • Magnetic energy
  • Electrostatic energy
  • Nuclear energy
  • Thermal energy
  • Elastic potential energy
  • Chemical energy
  • Kinetic energy
  • Gravitational potential energy
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4
Q

Name some examples of magnetic energy stores

A
  • Magnets
  • Compasses
  • Maglev trains
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5
Q

Name some examples of thermal energy stores

A
  • Human bodies
  • Hot coffee
  • Ice particles (vibrate slower but still have energy)
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6
Q

Name some examples of chemical energy stores

A
  • Food
  • Muscles
  • Electrical cells (eg. in batteries)
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7
Q

Name some examples of kinetic energy stores

A
  • Cars
  • Comets
  • Planets (orbiting)
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8
Q

Name some examples of electrostatic energy stores

A
  • Electricity
  • Thunderclouds
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9
Q

Name some examples of elastic potential energy stores

A
  • Elastic bands
  • Compressed springs
  • Inflated balloons
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10
Q

Name some examples of GPE energy stores

A
  • Planes
  • Hot air balloons
  • Jumping
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11
Q

Name some examples of nuclear energy stores

A
  • Nuclear bombs
  • Stars
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12
Q

What are the 4 different types of energy transfer?

A
  • Mechanical work
  • Electrical work
  • Heating
  • Radiation
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13
Q

What is mechanical work?

A

Energy transfer by a force moving an object through a distance

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14
Q

What is electrical work?

A

Energy transfer through an electrical current

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15
Q

What is heating (energy transfer)?

A

Energy transfer due to a temperature difference

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16
Q

What is radiation (energy transfer)?

A

Energy transferred as a wave

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17
Q

Energy cannot be _______ or _________

A

Created or destroyed

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18
Q

What is internal energy?

A

The total kinetic energy and potential energy of the particles in an object

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19
Q

What is the equation for GPE?
Give units.

A

GPE (J) = mass (kg) x gravitational field strength (N/kg) x height (m)

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20
Q

What is the equation for kinetic energy?
Give units.

A

KE (J) = 1/2 x mass (kg) x velocity2 (m/s)

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21
Q

What can be used to reduce friction between two moving things?

A

A lubricant

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22
Q

What is the equation for efficiency?

A

. Useful energy/power out
Efficiency = ————————————
Total energy/power in

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23
Q

What are the 3 different processes of which heat can be transferred?

A
  • Conduction
  • Convection
  • Radiation
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23
Q

Heat always moved from ___ areas to ____ areas

A

Hot areas to cold areas

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24
What is conduction?
When thermal energy is transferred through solids, through vibrations
25
What is convection?
When heat is transferred through either a liquid or a gas
26
What is this an example of? Conduction, convection or radiation The handle of a metal pan getting hot
Conduction
27
What is this an example of? Conduction, convection or radiation An oven cooking a turkey
Convection
28
What is this an example of? Conduction, convection or radiation A toaster making toast
Radiation
29
What is this an example of? Conduction, convection or radiation A metal at room temperature feels cold to touch
Conduction
30
What is this an example of? Conduction, convection or radiation Boiling a kettle
Convection
31
What is this an example of? Conduction, convection or radiation A white shirt keeps you cool in the summer
Radiation
32
When insulating something, is it better to have a high or a low thermal conductivity?
Low thermal conductivity
33
What is thermal conductivity?
A measure of how well a material conducts energy when it is heated
34
Name 4 methods you could use to prevent heat loss in a house
- Double glazed windows - Underfloor heating - Loft insulation - Thicker walls
35
How does double glazing help prevent heat loss?
Trapped air between the glass is a good insulator which therefore reduces heat loss
36
How does underfloor heating help to prevent heat loss?
Heat comes from the floor, so heat isn’t able to escape through there
37
How does loft insulation help prevent heat loss?
Trapped air is a good insulator which will therefore reduce heat loss
38
Name 2 ways to reduce unwanted energy transfers
- Lubrication - Thermal insulation
39
How does increasing a wall’s thickness reduce heat loss?
The energy must travel further before it is transferred to the outside
40
Name some renewable energy sources
- Solar - Wind - Hydroelectric - Geothermal - Bio-fuel - Tidal
41
Name the 2 non renewable sources of energy
- Fossil fuels - Nuclear
42
Name 3 different types of fossil fuels
- Oil - Coal - Natural gas
43
What are the disadvantages of fossil fuels?
- Non renewable - Releases CO2
44
What are the advantages of fossil fuels?
- Easy to gather - Easy to transport - Cheap / highly profitable
45
What are the disadvantages of nuclear power?
- Non renewable - Releases radioactive waste (needs to be disposed of safely)
46
How is energy gathered from fossil fuels?
Fossil fuels are burnt which turns turbines, producing electricity
47
How is energy gathered using bio-fuels?
Plant matter, ethanol or methane used in place of fossil fuels
48
How is energy gathered using wind?
Using wind turbines
49
How is energy gathered using hydroelectric?
Using hydroelectric dams
50
How is geothermal energy gathered?
Heat from underground can be used to create steam, which spins turbines, producing electricity
51
How is energy gathered using the sun?
Using solar panels
52
What are the advantages of nuclear power?
- Reliable - Produces no greenhouse gasses
53
What are the advantages of bio-fuel?
- Renewable - Carbon neutral
54
What are the disadvantages of bio-fuel?
- Expensive - Takes up a lot of land
55
What are the advantages of wind power?
- Renewable - Produced no greenhouse gasses - Land can still be used for farming
56
What are the disadvantages of wind power?
- Ugly - Kills birds - Only works if there is wind
57
What are the advantages of solar power?
- Renewable - Low environmental impact - Can be put on houses
58
What are the disadvantages of solar power?
- Only works if there is sun - Uses up lots of farmland
59
What are the advantages of geothermal energy?
- Renewable - Reliable - Low environmental impact
60
What are the disadvantages of geothermal energy?
- Harmful gasses could be released - Location specific
61
What are the advantages of tidal energy?
- Renewable - Reliable
62
What are the disadvantages of tidal energy?
- Not many suitable locations - Can harm marine habitats
63
What are the advantages of hydroelectric power?
- Renewable - Reliable
64
What are the disadvantages of hydroelectric power?
- Can cause flooding - Expensive to build the dam
65
Is the colour black a good absorber of heat?
Yes
66
Is the colour black a good emitter of heat?
Yes
67
Are white/shiny objects good at absorbing heat?
No
68
Are white/shiny objects good at emitting heat?
No
69
Other than releasing CO2, what is another environmental impact of burning coal?
Causes acid rain
70
What is power?
The rate at which energy is transferred
71
What causes mechanical processes to become less efficient?
When they produce heat, causing some of the energy to dissipate
72
Name an equivalent unit for watts
J/s (Joules per second)
73
What is work done?
The amount of energy transferred in order to move and object from one place to another
74
Can energy be created?
No
75
Can energy be destroyed?
No
76
What energy changes are involved when an object moves upwards (eg. if thrown)
**Kinetic energy** is transferred to **gravitational potential energy**
77
What energy changes are involved when a moving object hits a wall?
**Kinetic energy** is dissipated to various stores such as **thermal** stores
78
What energy changes are involved when a car is accelerating?
**Chemical energy** is transferred to **kinetic energy**
79
What energy changes are involved when a car is decelerating?
**Kinetic energy** is transferred to **thermal energy**
80
What is another name for thermal energy?
Internal energy