Energy

Question 1

What is the definition of energy?

Answer 1

The ability to do work

Question 2

What is energy measured in?

Answer 2

Joules

Question 3

What is Kinetic energy

Answer 3

Moving things have this

Question 4

What is Heat energy also known as?

Answer 4

Thermal energy

Question 5

How is sound energy produced?

Answer 5

Produced by vibrations, like a guitar string

Question 6

How is magnetic energy produced?

Answer 6

Produced by a magnet or electromagnet

Question 7

How is light energy produced?

Answer 7

Produced by sun, bulbs or fire

Question 8

Where is chemical energy stored?

Answer 8

Stored in all fuels, food and batteries

Question 9

How is electrical energy produced?

Answer 9

Produced when an electric current flows.

Question 10

Where is nuclear energy stored?

Answer 10

In nuclear fuels e.g. uranium

Question 11

Where is elastic potential energy stored?

Answer 11

In things that are stretched or compressed

Question 12

Where is gravitational potential energy stored?

Answer 12

• In things that are lifted up off the ground.
• The higher the are the more gravitational energy they have.

Question 13

What is the Law of conservation of energy?

Answer 13

Energy can neither be created nor destroyed; it can only be changed from one form to another.

Question 14

What forms of energy are often thought of as wasted energy?

Answer 14

Heat and sound.

Question 15

What does kinetic energy depend on?

Answer 15

Mass and speed

Question 16

What does gravitational potential energy depend on?

Answer 16

Mass and height

Question 16

What is the formula for kinetic energy

Answer 16

KE = ½mv²
KE - kinetic energy in Joules (J)
m - mass in kg
v - velocity in m/s

Question 17

What is the formula for potential energy?

Answer 17

• PE = mgh
• PE - potential energy in Joules (J)
• m - mass in kg
• g - acceleartion due to gravity = 10m/s
• h - height in m

Question 18

What is the link between kinetic energy and potential energy

Answer 18

KE at the bottom of eg a cliff = PE at the top if eg a cliff

Question 19

What are the 3 problems with fossil fuels?

Answer 19

1. Non-renewable: Once they are used up they can not be replaced easily or quickly
2. Produce carbon dioxide when burnt contributing to global warming
3. Release other pollutants e.g. sulphur dioxide gas which causes acid rain.

Question 20

What are fossil fuels?

Answer 20

Include coal, oil, gas and lignite. Used to heat homes, cook food, fuel transport and generate electricity

Question 21

Name 5 sources of renewable energy

Answer 21

• Wind
• Water
• Geothermal (energy from the ground)
• Solar
• Biomass (energy from animal or plant material)

Question 22

How does wind energy work?

Answer 22

Wind turns a wind turbine which generates electricity.

Question 23

What are the advantages for wind energy?

Answer 23

• Renewable energy source
• Does not release harmful gases
• No fuel costs

Question 24

What are the disadvantages for wind energy?

Answer 24

- Wind turbines can make a lot of noise - Some people think wind turnbines spoil the landscape - Unreliable source as the amount of electricty depends on how windy it is.

Question 25

What are the 3 methods of generating electricity using water?

Answer 25

- Tidal - Wave - Hydroelectric

Question 26

How does tidal energy work?

Answer 26

- Large amounts of water moves in and out of a river mouth each day due to tides - A tidal barrage is a barrier built across a river estuary, this contains electricity generators that are driven by the water rushing through tubes as a result of the tide

Question 27

How does wave energy work?

Answer 27

- Water in the sea rises and falls due to waves. - Wave machines move with the waves to drive generators

Question 28

How does hydroelectric energy work?

Answer 28

- Hydroelectric power stations use moving water. Water is held behind a dam built across a river. - Water high up behind the dam has a lot of gravitational potential energy. This is transferred to kinetic energy as the water rushes down the hill, the moving water turns a turbine that generates electricity.

Question 29

What are the advantages for water energy?

Answer 29

- No fuel costs - No harmful gases released - Tidal and hydroelectric are reliable sources of power

Question 30

What are the disadvantages for water energy?

Answer 30

- Waves are not a reliable source of power - Building dams and tidal barrages can harm habitats and displace people

Question 31

How does geothermal energy work?

Answer 31

Hot water/steam from deep underground can be used to turn a turbine and generate electricity.

Question 32

What are the advantages for geothermal energy?

Answer 32

- Reliable energy source - No fuel costs - No harmful gases produced - Can also be used to heat buildings

Question 33

What are the disadvantages for geothermal energy?

Answer 33

- Big investment needed to set up - Most parts of the world do not have suitable areas to exploit geothermal energy

Question 34

How does solar energy work?

Answer 34

Radiation from the sun can generate electricty in solar cells or warm water in solar panels

Question 35

What are the advantages for solar energy?

Answer 35

- Renewable energy source - Does not release harmful gases - No fuel costs

Question 36

What are the disadvantages for solar energy?

Answer 36

- Unreliable energy source as depends on how much sunlight there is. - Solar panels are expensive to fit.

Question 37

How does biomass energy work?

Answer 37

Biomass is burnt to turn water into steam. Steam turns turbines generating electricity.

Question 38

What are the advantages for biomass energy?

Answer 38

- Renewable energy source - Growing more crops takes in carbon dioxide. This can offset what is given out during burning (Carbon neutral)

Question 39

What are the disadvantages for biomass energy?

Answer 39

- Gases and smoke are released while burning the biomass - Lots of land is needed to grow crops