P1.6 Energy (forms of energies, disadvantages and advantages)

Question 1

Describe how energy from fossil fuels can be obtained ?

Answer 1

• Fossil fuels are burnt to generate electrical power.
• Their chemical energy is transferred to heat energy used to boil water, which creating steam that turns the turbine.

Question 2

How can energy be used to generate electrical power ?

Answer 2

• A turbine is turned using energy from an energy resource.
• The turbine turns coils, in a magnetic field, in a generator, this generates electrical power

Question 3

Describe how energy from biofuels can be obtained ?

Answer 3

• Biofuels are burnt to generate electrical power
• Their chemical energy is transferred to heat energy used to boil water, which creating steam that turns the turbine.

Question 4

Describe how energy from water can be obtained ?

Answer 4

1. Waves and tides: The kinetic energy as waves and tides move is used to turn underwater turbine
2. Hydroelectricity dam:
   + Water behind the dam is above ground level so has gravitational potential energy.
   + This energy is transferred to kinetic energy when water is released down the slope; the flowing of water turns the turbine

Question 5

Describe how energy from geothermal resources can be obtained ?

Answer 5

• As radioactive elements decay, their geothermal energy heats surrounding rocks
• Water is poured into shafts in the hot rock, heat energy boils water creating steam and returned via another shaft; this steam then turns the turbine

Question 6

Describe how energy from nuclear fission can be obtained ?

Answer 6

• Heat energy is released by nuclear fission; used to boil water creating steam and turns the turbine.

Question 7

Describe how energy from the sun can be obtained ?

Answer 7

1. Light from Sun: Solar energy from sunlight is turned into an electric current by solar cells
2. Sun’s light can be used to heat water
   + Infrared waves of the sun’s light heat water, contained with solar panels
   + The water goes to a tank and is stored for later use; a boiler might be needed to heat the water further
3. Sun heats the atmosphere, creating wind which can also generate electricity:
   + As wind blows, it transfers kinetic energy to the blades of wind turbines.

Question 8

Definition of energy

Answer 8

The quantity which is transferred whenever we observe a change; it is stored and can be transferred

Question 9

Energy can be stored in 7 ways:

Answer 9

Kinetic energy, gravitational potential energy, chemical energy, elastic energy, nuclear energy, electrostatic energy and internal (thermal) energy

Question 10

Define kinetic energy

Answer 10

Energy stored in any object that is moving

Question 11

Define gravitational potential energy

Answer 11

The energy stored in an object that is raised up against the force of gravity

Question 12

Define chemical energy

Answer 12

Energy stored in bonds between atoms that can be released when chemical reactions take place.

Question 13

Define elastic energy

Answer 13

Energy stored in ab object that is stretched or compressed

Question 14

Define electrostatic energy

Answer 14

Energy stored when charges are separated or squash together

Question 15

Define nuclear energy

Answer 15

Energy stored in the nucleus of an atom

Question 16

Define internal (thermal) energy

Answer 16

Total energy of an object, total kinetic and potential energies of its particles

Question 17

Advantages and disadvantages of solar energy

Answer 17

Advantages:
+ Renewable
+Does not contribute to global warming
+ No fuel cost
Disadvantages:
+ Unreliable: Intensity of sunlight varies, drop to zero at night
+ A large area of solar panels is required to capture energy
+ Expensive initial building costs

Question 18

Advantages and disadvantages of wind energy

Answer 18

Advantages:
+ Renewable
+Does not contribute to global warming
+ No fuel cost
Disadvantages:
+ Unreliable: speed of wind varies, so on calm days, now power is produced
+ Can be noisy
+ Takes several hundred win turbines to produce same energy as a fossil fuel power station

Question 19

Advantages and disadvantages of waves energy

Answer 19

Advantages:
+ Renewable
+ Does not contribute to global warming
+ No fuel cost
Disadvantages:
+ Unreliable: Height of waves varies; when there are no waves, no power is produced
+ The cost is high because these machines corrode in saltwater and can be damaged in storms

Question 20

Advantages and disadvantages of hydroelectricity

Answer 20

Advantages:
+ Renewable
+Reliable, safe and clean
+ Very short start up time, so energy is produced quickly
+ No fuel cost
Disadvantages:
+ Expensive initial building costs
+ Building dams and reservoirs may made people become homeless, wildlife loses their habitats

Question 21

Advantages and disadvantages of biofuels

Answer 21

Advantages:
+ Renewable
+Does not contribute to global warming
+ Reliable: can be burnt when needed
Disadvantages:
+Burning fuels indoor can affect health
+ Land is sometimes used for growing biofuels rather than food

Question 22

Advantages and disadvantages of fossil fuels (coal, oil, natural gas)

Answer 22

Advantages:
+ Produce a large amount of energy
+Reliable: We can burn more fuel when more electricity is needed
Disadvantages:
+ Not renewable
+ Releases carbon dioxide to the atmosphere adds to greenhouse effect and contribute to global warming
+ Burning coal and oil produces sulphur dioxide that leads to acid rain, damage infrastructure and ecosystems

Question 23

Advantages and disadvantages for nuclear energy

Answer 23

Advantages:
+ Provides a lot of energy from a small mass of fuel
+Reliable: nuclear fission provides energy for many years
Disadvantages:
+ Not renewable
+ Waste is radioactive
+Accidents at power stations can be catastrophe
+Expensive to build power station and to decommision

Question 24

Advantages and disadvantages for geothermal energy

Answer 24

Advantages:
+Renewable
+Reliable: the Earth is always hot internally
+ Does not contribute to global warming
+ No fuel cost
Disadvantages:
+ Only available at a few places on Earth where hot rocks are close enough to the surface

Question 25

Advantages and disadvantages for tidal energy

Answer 25

Advantages: + Renewable + Does not contribute to global warming +Reliable: Tides always happen twice a day + Does not contribute to global warming + No fuel cost Disadvantages: + Expensive initial building costs + Build tidal power stations can destroy habitat for wildlife +The barrage can block shipping routes

Question 26

State radiation from the Sun is the main source of energy for ...

Answer 26

Radiation from the Sun is the main source of energy for for all our energy resources except geothermal, nuclear and tidal

Question 27

Where is the energy released by the Sun comes from?

Answer 27

- Energy is released by nuclear fusion in the Sun - Nuclear fusion is where two small, light nuclei collide at high speed and join together to make one heavy nucleus.

Question 28

Where is the energy released from in nuclear reactors ?

Answer 28

- Energy is released by nuclear fission in nuclear reactors.