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Flashcards in Energy. 2 Deck (69)
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1
Q

Name all 8 energy stores.

A
Magnetic
Kinetic
Thermal
Nuclear
Elastic
GPE 
Chemical
Electrostatic
2
Q

Name all 6 way of how energy is transferred.

A
Heat
Light
Electrically
Chemically
Radiation
Sound
3
Q

What is a system?

A

A group or a single object.

4
Q

What happens when a system changes?

A

Energy is transferred into or away from the system or between energy stores.

5
Q

What does it mean by closed system?

A

No energy or matter can enter or escape. So its net change in the total in a closed system is 0.

6
Q

Give the equation and definition for Kinetic Energy.

A

Anything which moves has a kinetic energy store.

Ke= 1/2 x Mass (kg) x V2 (s)

7
Q

Give the equation and definition for GPE.

A

Any raised object has a gravitatinol store.

Gpe= m (kg) x g (n) x h (m)

8
Q

Give the equation and definition for elastic potential energy.

A

When an object is squashed or stretched it has an elastic potential energy.
Ee = 1/2 x K (n) x E2 (m)

9
Q

Give the equation and definition for specific heat capacity.

A

The amount of energy needed for the temperature to increase by 1 degrees to a 1 Kg object.
Ec= M (kg) C (j/kg) x CT (°C)

10
Q

What is the conservation of energy?

A

Energy cannot be created or destroyed only transferred.

11
Q

Is all energy transferred usefully?

A

No some energy is dissipated. Which means it is wasted as it is not useful.

12
Q

Describe energy transfers in closed systems.

A

Energy is transferred within the system but no energy has left and the net change is 0.

13
Q

Give the two equations to find power.

A
Power= Work / Time
Power= Energy / Time
14
Q

Define conduction.

A

process where vibrating particles transfer energy to neighbouring particles.

15
Q

How is energy transferrred in conduction.

A

By heating is transferred to its thermal store then shared across kinetic store of all the particles.

16
Q

What happens to particles in conduction when heated.

A

They vibrate so there are more collisions These collisions cause energy to be transferred to the particles kinetic store.

17
Q

Does conduction mean that it continues throughout the object?

A

Yes it will until it reaches the other side.

18
Q

What is thermal conductivity?

A

The measure of how quickly energy is transferred.

19
Q

What is the difference between conduction and convection?

A

Conduction SOLIDS

Convection LIQUIDS and GAS

20
Q

What is convection.

A

Energetic particles move away from the hotter to cooler regions.

21
Q

How is energy transferred in convection?

A

By heating to the thermal stores. Then kinetic energy is shared upon all particles.

22
Q

What happens to particles in conection when heated.

A

The particles in the region move faster and the space between them increases. But the density and the region decreases.

23
Q

What does heating a room with a radiator need?

A

Convection curents in the air in the room.

24
Q

How is energy transferred from a radiator?

A

Conduction, air particles collide with radiator surface.
Air near R is warmer and less dense.
Warm air rises and replaced by cool air.
Cool air heated.
At the same time previously heated air transfers energy to the surroundings it cool desnses and sinks.
Cycle repeats causing a flow of air A CONVECTION CURRENT.

25
Q

How does lubrication reduce frictional forces?

A

When something moves at least one frictionl force is against it.
Which causes energy to be dissipated.
Objects which are rubbed together lubricants reduce the friction so they can flow easily between them and coat them.

26
Q

Give some examples of lubricants.

A

Oil,Petrolum Jelly.

27
Q

How does Cavity wall insulations help reduce the rate of energy transfer?

A

In the cavity it is filled wiht foam to help reduce energy transfe by convection.

28
Q

How does Double Glazing insulations help reduce the rate of energy transfer?

A

Have an air gap between sheets of glass to prevent energy transfer by conduction.

29
Q

How does Loft insulation help reduce the rate of energy transfer?

A

can reduce convection currents created in lofts.

30
Q

How does Draught Excluders insulations help reduce the rate of energy transfer?

A

Around doors and windows reduce energy transfer by convection.

31
Q

What does it mean if something is efficent?

A

The amount of energy that is wasted tells us how effiecient the device is.

32
Q

How do you make something more efficient?

A

Insulating
Lubricating
Streamlining

33
Q

Give the two equations to find efficency.

A
E= Useful output energy transfer ÷ total input energy transfer.
E= Useful power output ÷ Total power input
34
Q

No device is 100% efficent but what is the exception?

A

Electrical heaters as all the electrostatic energy is transferred usefuly to the thermal energy store.

35
Q

Name 3 non-renewable resources.

A

Oil
Gas
Coal

36
Q

Describe what a non-renewable energy resource is?

A

They will run out.
Damage the environment.
Provide most of our energy.

37
Q

Name 7 Renewable energy resources.

A
Solar
Water waves
Geothermal
Hydroelectric
Biofuel 
Wind
Tides
38
Q

Describe what a renewable energy resource is?

A

Never run out
Less damaging than non-renewable.
Unreliable
Dont provide as much energy.

39
Q

How are energy sources used?

A

Heating

Transport

40
Q

How is non-renewable energy sources used in transport?

A
Oil = petrol and diesel.
Coal= Boil water to create steam for trains..
41
Q

How is renewable energy sources used in transport?

A

Biofuel- Vehicles run on biofuel only.

42
Q

How is non- renewable energy sources used in heating?

A

Natural gas= heats water then pumped into radiators.
Coal in fireplaces
Electric heaters = uses electricity from non-renewable.

43
Q

How is renewable energy sources used in heating?

A

Geothermal heat pump heats buildings.
Solar heats water for radiators
Burning biofuel generates electricity for heating.

44
Q

What is a wind turbine?

A

These devices are placed on moors which hae generators and the rotating blades generate electricity.

45
Q

Give some advantages of wind turbines.

A

No pollution
No fuel costs and minimal running costs.
No permanent damage to the landscape.

46
Q

Give some dis-advantages of wind turbines.

A

Not asthetically pleasing.
1500 turbines to replace on coal fire station.
Noisy.
If there is no wind impossible to meet the demand.
High initial costs.

47
Q

What are solar cells?

A

Generate electricity from sunlight.

48
Q

Give some advantages of solar cells.

A

No pollution.
Sunny countrys very reliable. And cost effective in cloudy countries.
Energy is free and running cost small.

49
Q

Give some disadvantages of solar.

A

Expensive to install.
Initial costs are high.
You cant increase the power output and not enough to meet demands.

50
Q

What is geothermal power.

A

Slow decay of radioactive elements ie uranium.

51
Q

Give some

advantages of geothermal.

A

Free
Reliable
Little co2

52
Q

Give some disadvantages of geothermal.

A

Arent many suitable locations for plants
costs more to install than it produces
only allowed in volcanic areas.

53
Q

What is hydroelectric power?

A

Flooding of a dam then in a generator.

54
Q

What are the advantages of HE?

A

No pollution
Imediate response to high demand.
No fuel costs and minial running costs.

55
Q

Give some disadvantages of H.E.

A
Flooding of the valley rots vegetation and releases co2.
Habitat loss
Reliable except in time of drought.
Small scale.
Looks unsightly.
56
Q

What is wave power?

A

Wind moves the turbines in waves to create energy.

57
Q

Give some advantages of wave power.

A

no pollution
no fuel costs
minimal running costs
useful on small islandsd.

58
Q

Give some disadvantages of wave power.

A
disturbs seabed
marine animal habitats spoilt
view
unreliable 
not large scale
59
Q

Whgat are tidal barrages

A

big dams built across river estuary with turbines it fills then is released.

60
Q

Give some advantages of tidal barrages.

A

No pollution
Reliable
produce signifigant amount of energy

61
Q

Give some disadvantages of tidal barrages

A

Initial costs are high
prevent free access to boats
kill marine life

62
Q

What is biofuel

A

Dung of plants and animals

63
Q

Disadvantages of biofuel

A
cannot respond to immediate demands
costs are high
plants are burned people are worried there are not enough crops to eat if we burn them all,
Forests cleaned wildlife killed
Burning causes co2
64
Q

Advantages of Biofuel

A

Carbon neutral

Reliable always crops

65
Q

How are non-renewables reliable?

A

meet current demand

Set up cost is high but gives more.

66
Q

How do non renewable cause environemental problems?

A

Co2
Burning them release co2 and sulfur dioxide causes acid rain harms trees and soil
coal mining spoils view
oil spills kill whales
Nuclear waste hard to dispose.
Nuclear power stations cost to decomision
Nuclear power = disaster ie fukushima

67
Q

Over the 20th century did energy demand increase

A

Yes as population grew then in 21st things became more efficient so it decreased

68
Q

Why do people want to use more renewables?

A

damages the environment
runs out
pressure from public
Car companies dealt with attitudes and made hybrids

69
Q

Why do people not want renewables?

A
Making changes ie hybrids are expensive
research to increase reliability is costy
Cant reach demands 
Wind farms are ugly
Power plants are
expensive
People have to pay for plants in taxes