Energy and Thermal Flashcards
(43 cards)
1
Q
What is the kinetic energy equation?
A
1/2 mass x velocity^2
2
Q
What is gravitational energy?
A
mass x gravitational field strength x change in height
3
Q
What is the unit of gravitational field strength?
A
- Measured in newtons per kilogram (N/kg)
4
Q
What is the unit of specific heat capacity?
A
- Measured in joules per kilogram per degree (J/kg°C)
5
Q
What is power?
A
- work done = force x distance
- power = energy transferred / time
- Energy transferred per second
6
Q
What is the law of conservation of energy?
A
- Energy can be transferred usefully, stored, or dissipated
- But it cannot be created or destroyed
7
Q
What are the non-renewable energy resources on earth?
A
- Fossil fuels
- Nuclear fuel
8
Q
What are the renewable energy resources on earth?
A
- Bio-fuel
- Wind
- Hydroelectricity
- Geothermal
- Tidal
- Solar
9
Q
Define renewable energy
A
- Energy derived from natural sources that are replenished at a higher rate than they are consumed
10
Q
Define non-renewable energy
A
- Comes from sources that will run out or will not be replenished (finite)
11
Q
Advantages and disadvantages of Fossil Fuels
A
- Reliable, can produce large amounts of energy consistently
- Can respond to changes in demand (can power on/off quickly)
- Produces CO2 which contributes to global warming
- Produces sulphur dioxide which causes acid rain
12
Q
Advantages and disadvantages of Nuclear power?
A
- Reliable, can produce large amounts of energy consistently
- Produces no pollution or CO2
- Large amounts of energy are produced from small amounts of fuel
- Produces radioactive waste that takes thousands of years to decay and must be safely disposed of
- Power stations are expensive to build and maintain and may take many years to be build
- Cannot respond to changes in demand as it cannot be turned on and off quickly
13
Q
Advantages and disadvantages of bio fuels?
A
- The CO2 released from combustion is balanced by the CO2 absorbed in photosynthesis so it can be considered carbon neutral
- Occupies land and uses resources used to grow crops
14
Q
Advantages and disadvantages of wind?
A
- Produces no pollution or CO2
- Cheap to build and maintain
- Non-reliable, only generates electricity when the wind is blowing a certain direction
- Considered as a visual pollution
15
Q
Advantages and disadvantages of hydroelectric?
A
- Reliable, can respond to meet changes in demand
- No pollution or CO2 produced
- Can involve flooding large areas to build reservoirs which destroys habitats and displaces wildlife
16
Q
Advantages and disadvantages of tidal?
A
- Very predictable so energy can be produced at regular intervals
- Few suitable locations
- Can harm aquatic life and sirupt shipping
17
Q
Advantages and disadvantages of geothermal?
A
- Reliable, energy efficient
- Not many suitable locations
- Can release methane in the extraction process
18
Q
Advantages and disadvantages of solar?
A
- Produces no pollution or greenhouse gases
- Good for electricity production in remote areas
- Non-reliable only generates electricity when the sun is shining
- Each solar cell only produces a small amount of electricity so many cells are needed
19
Q
Kinetic Energy Store
A
- Filled when an object speeds up
- Emptied when an object slows down
20
Q
Gravitational Energy Store
A
- Filled when an object moves away from earth
- Emptied when an object moves towards earth
21
Q
Chemical Energy Store
A
- Filled when a battery is recharged
- Emptied when a battery is discharged
22
Q
Elastic Potential Energy Store
A
- Filled when an object is stretched or compressed
- Emptied when the object regains its original shape
23
Q
Thermal Energy Store
A
- Filled when the object heats up
- Emptied when the object cools down
24
Q
Nuclear Energy Store
A
- Filled when unstable nuclei are formed
- Emptied when unstable nuclei decay to more stable nuclei
25
Magnetic Energy Store
- Filled when magnetic field is strengthened
- Emptied when magnetic field is wweakened
26
Electrostatic Energy Store
- Filled when electric field is strengthened
- Emptied when electric field is weakened
27
Mechanical Transfer
- Used to transfer energy when a force moves through a distance
28
Heating Transfer
- Used to transfer energy from hot to cold when there is a difference in temperature
29
Electrical Transfer
- Used to transfer energy via an electric current
30
Sound Radiation Transfer
- Used to transfer energy via longitudinal vibrations in matter
31
Light Radiation Transfer
- Used to transfer energy via electromagnetic radiation
32
Thermal Energy Store of the Surroundings
- Filled when energy is dissipated
- Via heating pathway, when energy is 'wasted' in processes which are no 100% efficient
33
Potential Energy
- The energy stored within an object due to its position, state or shape
34
What is Energy?
- Amount of work a body/system can do
- Measured in Joules (J)
35
What is conduction?
- Thermal energy is transmitted through materials from one vibrating particle to another
36
What is convection?
- Thermal energy is transmitted from one place to another by the movement of convection currents due to the differences in density
37
What is radiation?
- Transfer of energy by electromagnetic waves
38
What is black body?
- A perfect emitter and absorber of electromagnetic radiation
39
What is a Sankey diagram?
- Diagram representing energy transfers by a device to scale
40
What is the equation for stopping distance?
stopping distance = thinking distance + braking distance
41
What factors affect thinking distance?
- Driver being distracted
- Driver being tired
- Driver under influence of alcohols or drugs
- Higher speed
42
What factors affect braking distance?
- Higher speed
- Higher mass of car
- Slippery road surface
- Worn out brakes
43
Equations for constant acceleration?
- v^2 = u^2 + 2as
- a = (v-u)/t
