6.1.1 - Energy Changes In A System, And The Ways Energy Is Stored Before/after Such Changes Flashcards
1
Q
What’s a system
A
An object or group of objects
2
Q
What happens to energy when a system changes
A
The way energy is stored changes
3
Q
How does the way energy’s stored change when an object is projected upwards
A
Energy transfers from the kinetic energy store to the gravitational potential energy store
4
Q
How does the way energy’s stored change when a moving object hits an obstacle
A
Energy transfers from the kinetic energy store to the surrounding energy stores
5
Q
How does the way energy is stored change when an object is accelerated by a constant force
A
Energy transfers from the chemical energy store to the kinetic energy store
6
Q
How does the way energys stored change when a veichle slows down
A
Energy transfers from the kinetic energy store to the thermal energy store of the surroundings
7
Q
How does the way energy’s stored change when bringing water to boil in a electric kettle
A
The thermal energy of the kettles heating is transferred to the thermal energy store of the water
8
Q
What’s the equation for a change in energy when a systems changed by heating
A
- Change in thermal energy when= mass x specific heat capacity x temperature change
- ∆E = m x c x ∆θ
9
Q
What is the change in thermal energy measured in (∆E)
A
Joules (J)
10
Q
What is the mass measured in (m)
A
Kilograms (kg)
11
Q
What’s the specific heat capacity measured in (c)
A
Joules per kilogram per degree Celsius ( J/kg °C )
12
Q
What’s the temperature change measured in (∆θ)
A
Degrees Celsius (°C)
13
Q
What’s the equation for the change in energy when a systems changed is changed by work done by forces
A
- Work done = force x distance
- W = F x s
14
Q
What’s work done measured in (W)
A
Joules ( J )
15
Q
What’s force measured in (F)
A
Newtons (N)
16
Q
What’s distance measured in (s)
A
Metres (m)
17
Q
What’s the equation for calculating the change in energy energy when a systems changes by work done when a current flows
A
- work done = charge x voltage
- W = Q x V
18
Q
What’s work done when measured in (W)
A
Joules ( J )
19
Q
What’s charge measured in (Q)
A
Coulombs (C)
20
Q
What’s voltage measured in
A
Volts (V)
21
Q
Kinetic energy equation
A
- kinetic energy = 1/2 x mass x speed²
- Ek = 1/2 x m x v²
22
Q
What’s kinetic energy measured in (Ek)
A
Joules ( J )
23
Q
What’s mass measured in (m)
A
Kilograms (kg)
24
Q
What’s speed² measured in (mv²)
A
Metres per second² (m/s²)
25
Elastic potential energy equation
- elastic potential energy store= 1/2 x spring constant x extension²
- EPE = 1/2 x k x e²
26
What’s elastic potential energy measured in (EPE)
Joules ( J )
27
What’s spring constant measured in (k)
Newtons per metre (N/m)
28
What’s extension measured in (e)
Metres (m)
29
What’s the gravitational potential energy equation
- gravitational potential energy = mass x gravitational field strength x height
- gpe = m x g x h
30
What’s gravitational potential energy measured in (gpe)
Joules ( J )
31
What’s mass measured in (m)
Kilograms (kg)
32
What’s gravitational field strength measured in (g)
Newtons per kilogram (N/kg)
33
What’s height measured in (h)
Metres (m)
34
What’s specific heat capacity of a substance
The amount of energy required to raise the temperature of 1 kilogram of the substance by 1 degree Celsius
35
How do you determine the specific heat capacity of one or more materials (practical)
1) measure the mass of the material using a balance
2) put the thermometer into the material and add a drop of water after to the hole to remove the air gap
3) measure the starting temp
4) insert the heater into the material, turn it on, start the timer
5) record the current/voltage
6) record the temp every minute for 10 mins
7) calculate the power of the heater (P=IV)
8) calculate the energy transferred by the heater (E=Pt)
9) plot a graph of temp against energy transferred
36
What’s the independent variable for the specific heat capacity practical
Work done
37
Dependant variable for specific heat capacity practical
- temp change
- current
- voltage
38
Control variable for specific heat capacity practical
- mass of material
- time
- room temp
- insulation
- heater
39
Risks of specific heat capacity practical
- heater
- glass thermometer
40
Potential errors of specific heat capacity practical
- air gap between thermometer + sides of hole in material
- not all electrical energy supplied to heater is transferred to block - some dissipated to surroundings
- random error using thermometer
41
Improvements for specific heat capacity practical
- add a few drops of water to hole to get better contact between thermometer + material
- wrap material in insulation to minimise heat loss to the room
- repeat investigation + calculate average
42
What’s power
The rate at which energy is transferred OR the rate at which work is done
43
What are the 2 power equations
1) power = energy transferred / time
- P = E / t
2) power = work done / time
- P = W / t
44
What’s power measured in (P)
Watts (W)
45
What’s energy transferred measured in (E)
Joules ( J )
46
What’s time measured in (t)
Seconds (s)
47
What’s work done measured in (W)
Joules ( J )
48
What does 1 watt equal
1 joule of energy transferred per second
49
Two identical cars (except their engine power) race the same distance. Who will reach the finish line faster?
The car with the more powerful engine - it’ll transfer the same amount of energy but over less time
50
Can energy be created or destroyed
No
51
Energy can be…..
Transferred usefully, stored or dissipated
52
What happens to some of the enrgy when you transfer it between stores
Some energys dissipated (wasted) into energy stores that arent useful
53
When you use a phone where is the energy usefully transferred from
From the chemical energy stores of the battery in the phone
54
When you se a phone where does some of the wasted energy go
Wasted energy goes to the thermal energy store
55
When a cold spoons dropped into an insulated flask of hot soup what does this form
A closed system
56
Where is energy transferred from in the soup
From the thermal energy store of the soup to the useless thermal energy store of the spoon
57
Why is the net change in energy 0 when the soup transfers energy
Energy transfers have occurred within the system but no energys left it
58
What does lubrication reduce
Frictional force
59
What does insulation reduce
The rate of energy transfer by heating
60
The higher the thermal conductivity the higher the….
Rate of energy transfer by conduction across the material
61
What makes a building cool more slowly
Thicker walls and the lower their thermal conductivity the slower the rate of energy transfer will be
62
Efficiency equation
Useful output/total input
63
How to improve efficiency
Insulating objects, lubricaiting objects, make objects more streamlined
64
What’s the main energy resources for use on earth
Fossil fuels
nuclear fuel
bio-fuel
wind
hydroelectricity
geothermal
the tides
the sun
water waves
65
The main Fossil fuels
Coal, oil, gas
66
What’s a renewable energy source
One thats being (or can be) replenished as its used
67
What are the uses of energy resources
Transport
Electricity generation
Heating
68
What are fossil fuels
Natural resources formed underground
69
features of a fossil fuel and nuclear fuel
- will run out one day
- damage the environment
- reliable
70
Are fossil fuels and nuclear fuel renewable or non-renewable
Non-renewable
71
Are solar, wind, waves, hydroelectricity, bio-fuel, tides, geothermal renewable or non-renewable
Renewable
72
Features of renewable energy resources
- never run out
- do damage the environment but less than non-renewable energy resources
- dont provide as much energy
- some can be unreliable as they depend on weather
73
Non-renewable enrgy resources in transport
- petrol and diesel powered veichles use fuel created from oil
- coal is used in some steam trains yo boil water to produce steam
74
Renewable energy resources in transport
Veicheles that run on pure bio-fuel or a mix of bio-fuel and petrol/diesal
75
Non-renewable energy resources in heating
- natural gas - heats water thats pumped into radiators throughout the home
- coal to burn fireplaces
- electric heaters - use electricity generated from non-renewable energy resources
76
Renewable energy resources in heating
- geothermal heat pump - uses geothermal energy resources to heat buildings
- solar water heaters - use the sun to heat water thats pumped into radiators in a building
- burning bio-fuel/using electricity generated from renewable energy resources
77
What energy store is wind energy
Kinetic
78
Whens wind energy used
Electricity generation
79
What is the power output for wind energy like
Very low
80
What impact does wind energy have on the environment
Takes up large areas that could be used for farming
Noisy
Ugly
81
What type of energy store is solar energy
Nuclear
82
What is solar energy used for
Electricity generation and heating
83
What’s the power output for solar energy
Dependant on the weather
Only available during daylight
84
Does solar energy have much impact on the environment
Theres little to none
85
What type of energy store is geothermal energy
Thermal
86
What is geothermal energy used for
Electricity generation and heating
87
What’s the power output for geothermal energy like
Medium
88
Does geothermal energy have an impact on the environment
It only does little damage
89
What type of energy store is hydroelectricity energy
Gravitational potential
90
What’s hydroelectricity energy used for
Electricity generation
91
What’s the power output like for hydroelectricity energy
Medium
92
What imaapct on the environment does hydroelectricity have
Local habitats may be lost by large areas that need to be flooded to build dams
93
What type of energy store is wave enrgy
Kinetic
94
What is wave energy used for
Electricity generation
95
What is the wave energy power output like
Low
96
What is the wave energys impact on the environment like
Very low
97
What type of energy store are fossil fuels
Chemical
98
What are fossil fuels used for
Transport, heating and electricity generation
99
What is the power output for fossil fuels like
High
100
What is the impact on environment by fossil fuels
Realaese carbon dioxide (causes global warming)
101
What type of energy store is nuclear energy
Nuclear
102
What is nuclear energy used for
Electricity generation
103
What is the power output for nuclear energy like
Very high
104
What impcto the environment does nuclear energy have
Radioactive waste (must be disposed of safely)
