Energy Flashcards

(30 cards)

1
Q

How is energy transferred?

A

Energy is transferred mechanically, electrically, by heating or by radiation

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2
Q

What is the kinetic energy equation?

A

1/2 mv^2

1/2 x mass x speed^2

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3
Q

What is energy measured in?

A

Joules

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4
Q

What is the gravitational potential energy equation?

A

Mgh

Mass x gravitation field strength x height

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5
Q

What is the elastic potential energy equation?

A

1/2 x spring constant x extension^2

1/2ke^2

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6
Q

What is the conservation of energy principle?

A

Energy can be transferred usefully, stored or dissipated, but can never be created or destroyed

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7
Q

There are two equations for power, name both of them.

A
Power = Energy transferred / time (s)
Power = Work done / time (s)
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8
Q

What is conduction and where does it occur?

A

Conduction is the process where vibrating particles transfer energy to neighbouring particles. Mainly occur in solids

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9
Q

What is convection and where does it occur

A

Convection is where energetic particles move away from hotter to cooler regions. Occur in liquids and gas

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10
Q

What do radiators do?

A

They create convection currents. Energy is transferred from the radiator to the nearby air particles by conduction. Air near the radiator gets warm, warm air rises, cool air sinks to replace rising air

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11
Q

Name the ways to reduce unwanted energy transfer.

A

Lubrication

Insulation

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12
Q

Name the ways you can insulate the house and describe them.

A

Cavity walls - made up of inner and outer wall with air in the gap, the air gal reduces the amount of energy transferred by conduction through the wall
Double glazed windows - work in the same way as cavity walls
Loft insulation - reduce convection currents being made in the loft
Draught excluders - near doors and windows reduce energy transfers by convection

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13
Q

What is the efficiency equation?

A

Efficiency = useful energy/total energy

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14
Q

Name non renewable energy resources.

A
Coal 
Oil
Natural gas
Petrol/diesel
Electric heaters
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15
Q

Name renewable resources

A
Sun
Wind
Water waves
Hydro - electricity 
Bio - fuel 
Tides
Geothermal
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16
Q

Describe what wind power is and it’s advantages and disadvantages.

A

Wind power is wind turbines the rotating blades turn the generator and produce electricity. They can spoil the view, they can be noisy, you need a lot of wind turbines. Advantages are there are no permanent damages to landscape, no fuel costs.

17
Q

What do solar cells do?

A

Solar cells generates electric currents directly from the sunlight.

18
Q

Disadvantages and advantages of solar cells.

A

Advantages - no environmental damage, energy is free after they have been fixed
Disadvantages - need the country to have sun and costs alot

19
Q

What is geothermal power?

A

The source of much of the energy is the slow decay of various radioactive elements deep inside the earth. Energy comes from underground thermal energy stores and is very reliable.

20
Q

Explain why the UK plans to use more renewable energy resources in the future.

A

We know fossil fuels is very damaging to environment. This makes people want to use more renewable energy resource that affect the environment less
Non renewable resources will run out one day better to get used to it before the day comes.

21
Q

Currently we still depend on fossil fuels, but what do we use fossil fuels on?

A

Most of our electricity is produced using fossil fuels and from nuclear powers. We burn fossil fuels on oil which is used for fuel cars, and gas is used to heat homes and cook food etc.

22
Q

The use of renewable resources is being limited by what?

A

Reliability
Money
Politics

23
Q

What does hydro electric power require?

A

Usually requires the flooding of a valley by building a big dam

24
Q

What are the disadvantages of hydro electric power?

A

Possible rotting of vegetation
Release of methane and carbon dioxide
Loss of habitat

25
What are the requirements for wave power?
You need lots of small wave - powered turbines located around the coast
26
What are the advantages of hydro electric powers?
Provides an immediate response to an increased demand for electricity
27
What are the disadvantages of wave power?
Disturbing the seabed and the habitats or marine animals | Fairly unreliable
28
What does tidal barrage do and how do they do it?
Used to generate electricity Tidal barrages are big dams built across river estuaries, with turbines. Tides come by the gravitational pull of sun and moon and fill up estuary.
29
Advantages of tidal barriages
No pollution | Reliable
30
Disadvantages of tidal barriages
Preventing free across by boats | Spoils the view