KO1 ENERGY Flashcards
1
Q
State the standard units for energy.
A
Joules (J)
2
Q
Name the store of energy associated with fuels.
A
The chemical energy store
3
Q
Name the store of energy associated with batteries.
A
The chemical energy store
4
Q
Describe the change in the chemical energy store as fuel is burned.
A
It decreases.
5
Q
Name the store of energy associated with nuclear fuels.
A
The nuclear energy store
6
Q
Name the store of energy associated with changes in speed.
A
The kinetic energy store
7
Q
Describe the change in the kinetic energy store as the speed of an object decreases.
A
It decreases.
8
Q
Name the store of energy associated with changes in height.
A
The gravitational potential energy store
9
Q
Describe the change in the gravitational potential energy store as the height of an object decreases.
A
It decreases.
10
Q
Describe how an object can be extended.
A
By stretching it.
11
Q
Describe how an object can be compressed.
A
By squashing it.
12
Q
Define elastic object.
A
An object that returns to its original size and shape after stretching or compressing.
13
Q
Define inelastic object.
A
An object that does not return to its original size and shape after stretching or compressing.
14
Q
Name the store of energy associated with extending and compressing objects.
A
The elastic potential energy store
15
Q
Describe the change in the elastic potential energy store as the extension of an object decreases.
A
It decreases.
16
Q
Describe the change in the elastic potential energy store as an object becomes more compressed.
A
It increases.
17
Q
Name the store of energy associated with magnetic objects.
A
The magnetic energy store
18
Q
Name the store of energy associated with charged objects.
A
The electrostatic energy store
19
Q
Name the store of energy associated with changes in temperature.
A
The thermal energy store
20
Q
Describe the change in the thermal energy store as the temperature of an object increases.
A
It increases.
21
Q
Name the eight stores of energy.
A
Chemical, electrostatic, magnetic, elastic potential, nuclear, thermal, kinetic and gravitational potential
22
Q
Name the transfer of energy associated with electric circuits.
A
Electrical transfer
23
Q
Name the transfer of energy associated with forces changing the motion of an object.
A
Mechanical transfer
24
Q
Name the transfer of energy associated with forces changing the shape of an object.
A
Mechanical transfer
25
Name the transfer of energy associated with waves.
Radiation transfer
26
Name the transfer of energy associated with an object emitting sound or light.
Radiation transfer
27
Name the transfer of energy associated with one object increasing the temperature of another.
Heating transfer
28
Name the four transfers of energy.
Electrical, mechanical, radiation and heating
29
Define work done.
When energy is transferred from one store to another.
30
State the standard units for work done.
Joules (J)
31
State the two variables that the size of the kinetic energy store depends on.
Mass and speed
32
In words, state the equation that links kinetic energy, mass and speed.
kinetic energy = 0.5 × mass × (speed)²
33
In symbols, state the equation that links kinetic energy, mass and speed.
Eₖ = ½mv²
34
State the standard units for mass.
Kilograms (kg)
35
State the standard units for speed.
Metres per second (m/s)
36
State the two variables that the size of the elastic potential energy store depends on.
Spring constant of the spring/elastic and the extension
37
In words, state the equation that links elastic potential energy, extension and spring constant.
elastic potential energy = 0.5 × spring constant × (extension)²
38
In symbols, state the equation that links elastic potential energy, extension and spring constant.
Eₑ = ½ke²
39
State the standard units for spring constant.
Newtons per kilogram (N/kg)
40
State the standard units for extension.
Metres (m)
41
State the calculation for establishing the extension of a spring given its final and initial length.
final length - initial length
42
State the calculation for establishing the compression of a spring given its final and initial length.
final length - initial length
43
State the three variables that the size of the gravitational potential energy store depends on.
Mass, gravitational field strength and height
44
In words, state the equation that links gravitational potential energy, gravitational field strength, height and mass.
gravitational potential energy = mass × gravitational field strength × height
45
In symbols, state the equation that links gravitational potential energy, gravitational field strength, height and mass.
Eₚ = mgh
46
State the standard units for height.
Metres (m)
47
State the standard units for gravitational field strength.
Newtons per kilogram (N/kg)
48
State the Earth's gravitational field strength.
9.8 N/kg
49
State the three variables that the change in the thermal energy store depends on.
Mass, specific heat capacity and change in temperature
50
In words, state the equation that links change in thermal energy, mass, specific heat capacity and change in temperature.
change in thermal energy = mass × specific heat capacity × change in temperature
51
In symbols, state the equation that links change in thermal energy, mass, specific heat capacity and change in temperature.
∆E = mc∆Θ
52
Identify this symbol: ∆
Delta
53
Identify what this combination of symbols represents: ∆Θ
Change in temperature
54
State the standard units for specific heat capacity.
Joules per kilogram per degree Celsius (J/kg°C)
55
State the standard units for temperature.
Degrees Celsius (°C)
56
State the calculation for establishing the change in temperature given a final and initial temperature.
final temperature - initial temperature
57
Define specific heat capacity.
The amount of energy required to raise the temperature of 1 kg of a substance by 1°C.
58
If a material has a relatively high value for specific heat capacity, state and explain whether it is relatively hard or easy to heat up.
Hard
It requires a lot of energy to raise the temperature of 1 kg by 1°C.
59
State the three variables that need to be measured to establish the specific heat capacity of a substance.
Energy supplied to the substance, mass of the substance and temperature increase of the substance
60
Name the piece of equipment used to measure temperature.
A thermometer
61
Name the piece of equipment used to measure mass.
A mass balance
62
Explain why a Bunsen burner is not used to heat a material when measuring specific heat capacity.
The amount of energy it supplies cannot be established easily.
63
Explain why an electrical heater is used to heat a material when measuring specific heat capacity.
It is possible to establish how much energy is supplied.
64
A student wants to measure the specific heat capacity of an iron block. Outline a method to do this. Ensure the method would lead to valid results.
Measure the mass of the block using a mass balance.
Measure the initial temperature of the block by inserting a thermometer.
Insert an electric heater into the block and turn it on.
When the temperature reading on the thermometer starts to increase, start a timer.
Record the current through the heater and potential difference across the heater for 10 minutes.
After 10 minutes, record the final temperature of the block.
Calculate the temperature change by subtracting the initial temperature from the final temperature.
Use the measurements of time, potential difference and current to calculate the energy supplied to the block.
Use the equation to calculate the specific heat capacity.
65
A student wants to measure the specific heat capacity of a range of materials. Name the independent variable.
The materials
66
A student wants to measure the specific heat capacity of a range of materials. Name the dependent variable.
Specific heat capacity
67
Define power.
The rate of energy transfer or the rate of work done.
68
Define rate.
How much a variable changes over time.
69
State the standard units for power.
Watts (W)
70
State the standard units for time.
Seconds (s)
71
Name an equivalent but non-standard unit for 1 W.
1 J/s
72
In words, state the equation that links power, energy transferred and time.
power = energy transferred ÷ time
73
In symbols, state the equation that links power, energy transferred and time.
P = E ÷ t
74
In words, state the equation that links power, time and work done.
power = work done ÷ time
75
In symbols, state the equation that links power, time and work done.
P = W ÷ t
76
Define closed system.
A system in which energy is conserved.
77
State the law of conservation of energy.
Energy cannot be created or destroyed, it can only be transferred between one store and another.
78
State the term used to describe energy that is transferred to stores but is not useful.
Wasted energy
79
State how unwanted energy transfers can be reduced.
By lubrication or thermal insulation.
80
Name the store of energy that the lubrication of moving parts will reduce energy transfers to.
The thermal energy store
81
Name the store of energy that using thermal insulation will reduce energy transfers to.
The thermal energy store
82
Describe the relationship between the thermal conductivity of a material and the rate of energy transfer through it by thermal conduction.
The larger the thermal conductivity of the material, the higher the rate of energy transfer through it by thermal conduction.
83
Name two variables that affect the rate of cooling of a building through its walls.
Thickness of the walls and thermal conductivity of the walls
84
Describe the relationship between the thickness of a building's walls and the rate of energy loss from the building.
As the thickness of the walls increases, the rate of energy loss decreases.
85
Describe the relationship between the thermal conductivity of a building's walls and the rate of energy loss from the building.
As the thermal conductivity of the walls increases, the rate of energy loss decreases.
86
Explain the purpose of using a good thermal insulator.
To reduce unwanted heating transfers.
87
Name the pieces of equipment required to compare the effectiveness of thermal insulators.
Volume of hot water in a beaker, different insulating materials, thermometer and timer
88
In an investigation to compare which thermal insulating material is most effective, name the independent variable.
Insulating material
89
In an investigation to compare which thermal insulating material is most effective, name the dependent variable.
Temperature change of the water being insulated
90
In an investigation to compare which thermal insulating material is most effective, name three variables that need to be controlled.
Volume of water, volume of insulation and time for cooling
91
Name the piece of equipment used to measure time.
A timer
92
Hot water is placed in a container and surrounded by a very good thermal insulator. Describe the effect this has on the water temperature over time.
The temperature decrease of the water will be small.
93
Hot water is placed in a container and surrounded by a very poor thermal insulator. Describe the effect this has on the water temperature over time.
The temperature decrease of the water will be large.
94
A student wants to measure the effect of multiple layers of insulation on the temperature change of a liquid in five minutes. Outline a method to do this. Ensure the method would lead to valid results.
Take a set volume of liquid in a beaker at a set temperature and measure the initial temperature.
Leave for five minutes and measure the final temperature.
Repeat with one layer of insulation.
Repeat with two layers of insulation, etc.
For each experiment, find the change in temperature by subtracting the initial temperature from the final temperature.
95
In terms of energy, define efficient.
Only a small percentage (or small fraction) of the input energy is wasted.
96
In words, state the equation that links efficiency, total input energy transfer and useful output energy transfer.
efficiency = useful output energy transfer ÷ total input energy transfer
97
State how the efficiency of a mechanical energy transfer can be increased.
By lubricating any moving parts to reduce friction.
98
State how the efficiency of a heating energy transfer can be increased.
By adding thermal insulation.
99
In words, state the equation that links efficiency, total input power and useful output power.
efficiency = useful output power ÷ total input power
100
Two torches each have an input power of 50 W. Torch A has a useful output power of 40 W. Torch B has a useful output power of 45 W. State and explain which torch is more efficient.
Torch B
It uses a greater percentage of the input power usefully.
101
Two heaters each have a useful output power of 2000 W. Heater A has an input power of 2500 W. Heater B has an input power of 2600 W. State and explain which heater is more efficient.
Heater A
It wastes a smaller percentage of the input power.
102
Name the three main uses for energy resources.
Transport, electricity generation and heating
103
Define renewable energy resource.
A resource that is being (or can be) replenished as it is used.
104
Name the nine main energy resources.
Fossil fuels, nuclear fuel, biofuel, wind, hydroelectricity, solar, geothermal, tidal and wave
105
Name the three types of fossil fuels.
Coal, oil and natural gas
106
Identify the two main non-renewable energy resources.
Fossil fuels and nuclear fuel
107
Name two energy resources which involve burning or combustion.
Fossil fuels and biofuel
108
In terms of energy resources, define reliable.
A resource that can be relied on to supply energy in a predictable way when needed.
109
Explain why solar power is not reliable in every country.
The amount of sunlight can change (due to weather).
110
Explain why wind power is not reliable in every country.
The amount of wind can vary.
111
Explain why fossil fuels are considered reliable.
They can be burned in varying amounts depending on demand.
112
Explain why hydroelectricity is considered reliable.
The flow of water through a dam can be adjusted depending on demand.
113
Identify the energy resource that contributes most negatively to climate change.
Fossil fuels
114
Other than climate change, name two important environmental factors when considering which energy resource to use.
Destruction of habitats and environmental cost of the building materials
115
Name two energy resources that can be used for transport involving internal combustion engines.
Fossil fuels and biofuel
116
Name the energy resources that can be used for electricity generation.
Fossil fuels, nuclear fuel, biofuel, wind, hydroelectricity, solar, geothermal, tidal and wave
117
Name the energy resources that can be used for heating.
Fossil fuels, biofuel, geothermal and solar
118
State four factors that go into a decision about which energy resource to use in an area.
Environmental, political, social and economic considerations
