Brainscape's Knowledge GenomeTM

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


See full index

Yr8-Science > y9 revision 2 > Flashcards

y9 revision 2 Flashcards

1
Q

list the 8 energy stores

A

thermal energy, chemical energy, nuclear energy, kinetic energy, elastic potential energy, magnetic energy, electrostatic energy, gravitational potential energy

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

name the four ways in which energy can be transferred

A

electrical, radiation, mechanical, heating

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

what is a closed system

A

where neither matter nor energy can enter or leave. the net charge in the total energy of closed system is always zero

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

what is the unit of energy?

A

joules (j)

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

what is gravitational potential energy equation, with units?

A

Ep= mgh
GPE = joules (j)
mass = kilograms (kg
height - metres (m)

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

what is the kinetic energy equation, with units?

A 
Ek = 0.5 mv^2 
KE = joules (j) 
mass = kilograms (kg) 
speed = metres per second (m/s)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is the law of conservation of energy?

A

energy is not created or destroyed but transferred from one store to another

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

what is the equation of power? with units

A 
P = E/t 
Power = watts (w) 
Energy = joules (j) 
Time = seconds (s)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

where is heat lost in a house?

A

windows, roof, walls, doors and floors

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

what is the efficiency equation?

A 
Efficiency = useful energy/ total energy 
Efficiency = useful power/ total power
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

define the term power

A

the rate of transfer of energy

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

describe the energy transfer when a moving car slows down

A

energy is transferred mechanically from the kinetic store of the car to the thermal store of the surrounding
some energy is dissipated to the thermal store of the surrounding

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

describe the energy transfer when electric kettle is used an elastic band

A

the electric current in a kettle transfers energy to the heating element’s thermal store of the surroundings

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

describe the energy transfer when battery powered toy car is used

A

energy is transferred electrically from chemical store of the battery to the kinetic store of the toy car - some of the energy is dissipated to the thermal store of the surrounding

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

describe the energy transfer when a falling apple hits the ground

A

energy is transferred from kinetic store of the apple and dissipated to the thermal store of surroundings by sound waves

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

name the unit that represents one joule transferred per second

A

watts (w)

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

what is work done?

A

energy transferred when force moves an object

18
Q

what would happen to the kinetic energy of the mass of the object double, but the speed stayed the same?

A

the kinetic energy would double

19
Q

what would happen to the kinetic energy of the speed of the object double, but the mass of the object stayed the same?

A

the kinetic energy would be quadruple

20
Q

what is the elastic potential energy equation, with units?

A

Ee= 0.5 ke^2
Elastic potential energy = joules (j)
spring constant = newton per meter (N/m)
extension = meter (m)

21
Q

what is meant by the term extension and spring constant?

A

extension is the charge in the length of the spring constant in the stiffness of the spring

22
Q

what is the meaning of specific heat capacity?

A

the specific heat capacity of a substance is the amount of energy required to raise the temperature of one kilogram of the substance by one degree Celsius

23
Q

what is the equation for specific heat capacity? with units

A 
△E = mc △0 (line in the 0) 
change in thermal energy, △E, in joules, J 
mass = kilograms, kg 
specific heat capacity, J/kg °C
temperate change = °C
24
Q

what is the dependent, independent and control variable for the specific heat capacity practical?

A

Independent variable is the energy transfer
dependent variable is the temperature change
control variable are insulation (quantity and type), same heater, same method of transferring energy

25
Q

describe the ways to reduce heat loss in a house

A

windows ~ double glazing, air gap between the two sheets of glass to prevent energy transfer by conduction
thick curtains ~ the cloth over the window creates air gap between the room and the window which reduces the energy transfer by conduction
roof ~ loft insulation, thick layer of fibreglass reduces conduction as it traps pockets of air
walls ~ cavity wall insulation, the air gap reduces the amount of energy transferred by conduction through the wall
doors ~ draught excluders, stops draught blowing in and out and reduces energy transfer by convection

26
Q

name the renewable and non - renewable resources of energy?

A

non - renewable ~ coal, oil , gas and nuclear

renewable ~ solar energy, wind turbine, waves, geothermal, tidal, hydroelectric, biomass

27
Q

list the advantages of fossil fuels

A

readily available
enough resource to meet the current demand. reliable source of energy
cheap to extract and use

28
Q

list the disadvantages fossil fuels

A

releases carbon dioxide into the atmosphere which contributes to global warming
releases sulphur dioxide into the atmosphere which causes acid rain
going to run out

29
Q

list the advantages of nuclear power

A

lots of energy releases from a small amount of fuel
reliable can control supply to match the demand
enough fuel available to meet the current demand
no polluting gases

30
Q

list the disadvantages of nuclear power

A

waste is dangerous and difficult and expensive to deal with
expensive initial set up
expensive to shut down and to run

31
Q

list the advantages of solar energy

A

can be used in remote places
no polluting gases
no waste products
very low running costs

32
Q

list the disadvantages of solar energy

A

unreliable
cannot control supply
initial set up expensive
cannot be used on a large scale

33
Q

list the advantages of wind power

A

clean renewable source of energy
relatively low set up cost pre unit of electricity generated
large potential both on and offshore in the UK
wind farms tend to produce more electricity in the winter when demand is also higher

34
Q

list the disadvantages of wind power

A

wind power is not reliable, if wind is light then no power generated
some people do not like the look of them
potentially harm some birds
some people do not want them near their home due to visual impact and noise

35
Q

list the advantages of tidal power

A 
now polluting gases 
no waste products 
reliable 
can produce large amounts of electricity 
low running cost 
no fuel costs
36
Q

list the disadvantages of tidal power

A 
can harm marine habitat 
initial set up expensive 
cannot increase supply when needed 
amount of energy varies on time of month 
hazard for boats
37
Q

list the the advantages of wave turbines

A

no polluting gases produced
no waste products
low running cost
no fuel cost

38
Q

list the advantages of wave turbines

A 
unreliable, dependent on weather 
cannot control supply 
initial set up expensive 
can harm marine habitats 
hazard for boats 
cannot be used on a large scale
39
Q

list the advantages of geothermal energy

A

clean and renewable
no air pollution or carbon dioxide production
minimal damage to the environment
constant source of energy

40
Q

list the disadvantages of geothermal energy

A

only a few places on Earth are suitable where the Earth’s core is close enough to the surface to make use of the geothermal energy
Expensive and difficult to drill deep into the ground

41
Q

list the advantages of biofuels

A

carbon neutral fuel as carbon dioxide is absorbed when growing so it does not add to the overall carbon dioxide in the atmosphere
can be used to replace the burning of fossil fuels like coal in power stations

42
Q

list the disadvantages of biofuels

A

emits carbon dioxide and soot when burnt
bulky to transport requiring large volumes for the same energy output compared to fossil fuels
requires energy to transport and process

Yr8-Science (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions