Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physics > P1 Energy Stores And Systems > Flashcards

P1 Energy Stores And Systems Flashcards

You may prefer our related Brainscape-certified flashcards:
Physics 101 flashcards AP® Physics flashcards
1
Q

What are the 8 energy stores?

A
  1. Thermal (or internal) energy
  2. Kinetic energy
  3. Gravitational potential energy
  4. Elastic potential energy
  5. Chemical energy
  6. Magnetic energy
  7. Electrostatic energy
  8. Nuclear energy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the 4 ways energy can be transferred?

A 
Mechanically (by a force doing work)
Electrically (work done by moving charges)
By heating
By radiation (e.g. Light or sound)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a system?

A

A system is a single object (e.g. The air in a piston) or a group of objects (e.g. Two colliding vehicles) that you’re interested in

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a closed system?

A

Systems where neither matter nor energy can enter or leave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What happens when a system changes?

A

Energy is transferred

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the conservation of energy principle?

A

Energy is always conserved: it can be transferred usefully, stored or dissipated, but can never be created or destroyed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is power?

A

The rate of energy transfer, or the rate of doing work

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is power measured in?

A

Watts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is one watt equivalent to?

A

1 joule of energy transferred per second

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the two equations to calculate power?

A 
P = E/t (power = energy transferred / time)
P = W/t (power = work done / time)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is a powerful machine?

A

one that transfers a lot of energy in a short space of time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is a method of reducing frictional forces?

A

lubrication

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is thermal conductivity?

A

a measure of how quickly energy is transferred through a material by particles colliding with each other

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how can you prevent heat from escaping out of your house into the atmosphere?

A
  • Have thick walls that are made from a material with a low thermal conductivity.
  • Use thermal insulation (cavity walls, loft insulation, double glazed windows, draught excluders)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the equation to work out efficiency?

A

……………….useful output energy transfer
efficiency = ____________________
………………….total input energy transfer

OR

……………………..useful power output
efficiency = _________________
………………………..total power input

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what device is 100% efficient?

A

electric heaters, and nothing else

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the most common store that waste energy is transported to?

A

thermal energy store

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

name two examples of non-renewable energy sources

A

fossil fuels and nuclear fuel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

name the three main fossil fuels

A

coal
oil
natural gas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

name seven renewable energy resources

A

1) the sun (solar)
2) Wind
3) Water waves
4) Hydro-electricity
5) Bio-fuel
6) Tides
7) Geothermal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

disadvantages of wind turbines:

A
  • they spoil the view
  • they’re noisy, which can be annoying for people who live nearby
  • reliant on the weather - have to stop when the wind stops or if it’s too strong - only produce electricity 70-85% of the time
  • it’s impossible to increase supply when there’s extra demand
  • initial costs are quite high
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

advantages of wind turbines

A
  • don’t produce pollution
  • renewable
  • no fuel costs and minimal running costs
  • no permanent damage to the landscape
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

disadvantages of solar power:

A
  • use quite a lot of energy to manufacture
  • can’t increase power output when there’s extra demand
  • initial costs are high
  • usually used on a relatively small scale
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

advantages of solar power

A
  • no pollution
  • renewable
  • reliable in sunny countries
  • almost no running costs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what is geothermal power?

A

energy from underground thermal energy stores

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

where can geothermal power be used?

A

in volcanic areas or where hot rocks lie quite near the surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

what is the main drawback of geothermal energy?

A

there aren’t very many suitable locations for power plants, and the cost of building a power plant is often high compared to the amount of energy it produces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

what does hydro-electric power use?

A

falling water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

does hydro-electric power have a big impact on the environment? why?

A

yes - it usually requires the flooding of a valley by building a big dam, and rotting vegetation releases methane and CO2. it could also cause a loss of habitat for some species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

advantages of hydro-electric power

A
  • no pollution produced directly
  • renewable
  • can provide an immediate response to an increased demand for electricity
  • no problem with reliability except in times of drought
  • no fuel costs and minimal running costs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

advantages of wave power

A
  • no pollution
  • no fuel costs and minimal running costs
  • can be very useful on small islands
32
Q

disadvantages of wave power:

A
  • it disturbs the seabed and habitats of marine animals
  • spoils the view
  • are a hazard to boats
  • fairly unreliable - waves die out when the wind drops
  • initial costs are high
  • likely never to provide energy of a large scale
33
Q

what is the most common way of using tides to generate electricity?

A

building a tidal barrage

34
Q

what are tidal barrages and how do they work?

A

tidal barrages are big dams built across river estuaries with turbines in them. As the tide comes in it fills up the estuary, and the water is then allowed out through turbines at a controlled speed

35
Q

advantages of tidal power

A
  • no pollution
  • renewable
  • tides are fairly reliable - happen twice daily without fail
  • no fuel costs and minimal running costs
  • has the potential for generating a significant amount of energy
36
Q

disadvantages of tidal power

A
  • preventing free access by boats
  • spoiling the view
  • altering the habitat of the wildlife
  • height of tides is variable
  • initial costs are moderately high
  • can only be used in some of the most suitable estuaries
37
Q

what are biofuels made from?

A

plants and waste

38
Q

advantages of biofuels

A
  • renewable
  • supposedly carbon neutral (though only true if you keep growing plants at the rate you’re burning things)
  • fairly reliable
39
Q

disadvantages of biofuels

A
  • cannot respond to immediate energy demands
  • the cost to refine bio-fuels is very high
  • large areas of forest have been cleared to make room to grow bio-fuels, resulting in lots of species losing their natural habitats. the decay and burning of this vegetation also increases CO2 and methane emissions
40
Q

advantages of fossil fuels and nuclear energy:

A
  • reliable
  • enough to meet current demand
  • can respond quickly to changes in demand
  • running costs aren’t that expensive
  • fossil fuels are a cost-effective way to produce energy
41
Q

disadvantages of fossil fuels

A
  • fossil fuels are slowly running out
  • set-up costs of power plants quite high
  • release CO2 - greenhouse effect + global warming
  • burning coal and oil releases sulfur dioxide, which causes acid rain
  • coal mining makes a mess of the landscape - the view can be spoilt by fossil fuel power plants
42
Q

how can acid rain be reduced?

A

taking the sulfur out before the fuel is burned, or cleaning up the emissions

43
Q

disadvantages of nuclear energy

A
  • nuclear waste is very dangerous and difficult to dispose of
  • the overall cost of nuclear power is high due to the cost of the power plant and final decommissioning
  • nuclear power always carries the risk of a major catastrophe like the Fukushima disaster in Japan
44
Q

why did the electricity use of the UK hugely increase over the 20th century?

A

the population grew and people began to use electricity for more and more things

45
Q

has electricity use in the UK increased or decreased since the beginning of the 21st century? has it done this quickly or slowly? why?

A

electricity use in the UK has been slowly decreasing as we get better at making appliances more efficient and become more careful with energy use in our homes

46
Q

what is most of our electricity produced using?

A

fossil fuels (mostly coal and gas) and from nuclear power

47
Q

why do people want to use more renewable energy resources?

A
  • we now know that burning fossil fuels is very damaging to the environment
  • people and governments are becoming increasingly aware that non-renewables will run out one day - it’s better to learn to get by without them before this happens
48
Q

what is the use of renewable energy limited by?

A

reliability, money and politics

49
Q

give two reasons why we currently do not use more renewable energy resources in the UK

A

any two from:

  • building new power plants is expensive
  • people don’t want to live near new power plants
  • renewable energy resources are less reliable than non-renewable energy resources
  • hybrid cars are more expensive than equivalent petrol cars
50
Q

what is another name for internal energy?

A

thermal energy

51
Q

what is always the net change in the total energy of a closed system?

A

0

52
Q

what is work done the same as?

A

energy transferred

53
Q

give two ways that work can be done

A
  1. when current flows

2. by a force moving an object

54
Q

describe the changes in energy stores when a ball is thrown into the air?

A

the initial force exerted by a person to throw a ball upwards does work. It causes an energy transfer from the chemical energy store of the person’s arm to the kinetic energy store of the ball and arm

55
Q

describe the changes in energy stores when a ball is dropped from a height?

A

a ball dropped from a height is accelerated by gravity. The gravitational force does work. It causes energy to be transferred from the ball’s gravitational potential energy store to its kinetic energy store

55
Q

describe the changes in energy stores when a ball is dropped from a height?

A

a ball dropped from a height is accelerated by gravity. The gravitational force does work. It causes energy to be transferred from the ball’s gravitational potential energy store to its kinetic energy store

56
Q

describe the energy transfers that occur when the wind causes a windmill to spin

A

energy is transferred mechanically [1 mark] from the kinetic energy store of the wind [1 mark] to the kinetic energy store of the windmill [1 mark]

57
Q

what does the amount of energy in an object’s kinetic energy store depend on?

A

the object’s mass and speed

58
Q

what is the formula for kinetic energy? give the units for everything

A 
Ek = 0.5 x m x v^2
kinetic energy (J) = 0.5 x mass (kg) x velocity^2 (m/s)
59
Q

what does the amount of energy in a gravitational potential energy store depend on?

A

the object’s mass, its height and the strength of the gravitational field the object is in

60
Q

what is the equation for gravitational potential energy (g.p.e)? give the units for everything

A

Ep = mgh

g.p.e (J) = Mass (kg) x gravitational field strength (N/kg) x height (m)

61
Q

for a falling object when there’s no air resistance, what is the relationship between the energy lost from the g.p.e store and the energy gained in the kinetic energy store? how does this change if there is air resistance?

A

when there is no air resistance, they are equal. However, in real life, air resistance acts against all falling objects - it causes some energy to be transferred to other energy stores, e.g. the thermal energy stores of the object and surroundings

62
Q

how can energy be transferred to an object’s elastic potential energy store?

A

stretching or squashing an object can transfer energy to its elastic potential energy store

63
Q

what is the equation for elastic potential energy? Give the units for everything

A

Ee = 0.5 x k x e^2

elastic potential energy (J) = 0.5 x spring constant (N/m) x extension (m)^2

64
Q

what are the units for gravitational field strength?

A

N/kg

65
Q

when can the equation for elastic potential energy not be used?

A

after the limit of proportionality has been exceeded

66
Q

what is specific heat capacity?

A

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

67
Q

give the equation that links energy transferred and specific head capacity

A

change in thermal energy (J) = mass (kg) x specific heat capacity (J/kg°C) x temperature change (°C)

68
Q

what are the units for specific heat capacity?

A

J/kg°C

69
Q

describe an investigation to find the specific heat capacity of a material

A
  1. set up a circuit that connects an ammeter and a heating element in series
  2. to investigate a solid material (e.g. copper), you’ll need a block of the material with two holes in it (for the heater and thermometer to go into)
  3. measure the mass of the block, then wrap it in an insulating layer (e.g. a thick layer of newspaper) to reduce the energy transferred from the block to the surroundings. Place the thermometer into the smaller hole and the heater into the larger one
  4. measure the initial temperature of the block and set the potential difference, V, of the power supply to be 10 V. Turn on the power supply and start a stop watch
  5. as the heater starts to heat the block up, take readings of the temperature and current, I, every minute for 10 minutes. You should find that the current through the circuit doesn’t change as the block heats up.
  6. when you’ve collected enough readings (10 should be enough), turn off the power supply. Using your measurement of the current, and the potential difference of the power supply, you can calculate the power supplied to the heater, using P = VI. You can use this to calculate how much energy, E, has been transferred to the heater at the time of each temperature reading using the formula E = Pt, where t is time in seconds since the experiment began
  7. if you assume all the energy supplied to the heater has been transferred to the block, you can plot a graph of energy transferred to the thermal energy store of the block against temperature
  8. find the gradient of the graph. This is (change in temperature)/(change in energy). Using the equation for specific heat capacity, you can determine that the shc of the material of the block is 1/(gradient x the mass of the block)
  9. you can repeat this experiment with different materials to see how their specific heat capacities compare
70
Q

how can the investigation to determine the specific heat capacity of a material be adjusted to work with liquids?

A

place the heater and thermometer in an insulated beaker filled with a known mass of the liquid.

71
Q

what is power?

A

the rate of energy transfer, or the rate of doing work

72
Q

what is power measured in? What does one of these measurements equal?

A

power is measured in watts. One watt = 1 joule of energy transferred per second

73
Q

give 2 equations to calculate pwer

A
  1. Power (W) = Energy transferred (J) / time (s)
    (P = E/t)
  2. Power (W) = Work done (J) / time(s)
    (P = W/t)
74
Q

what is a powerful machine?

A

a machine that transfers a lot of energy in a short space of time

Physics (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions