energy

Question 1

What is energy?

Answer 1

The ability or capacity to do work

Question 2

What is kinetic energy?

Answer 2

Energy an object has because it is moving

Question 3

What is chemical energy?

Answer 3

Energy found in foods, fuel and batteries

Question 4

What is thermal energy?

Answer 4

Energy stored in an object because of its temperature

Question 5

What is gravitational potential energy?

Answer 5

Energy an object has due to its position above the ground

Question 6

What is elastic potential energy?

Answer 6

Energy an object has because it has been deformed or stretched

Question 7

What is electrostatic energy?

Answer 7

Energy due to the force of attraction/repulsion between two charged objects

Question 8

What is magnetic energy?

Answer 8

Energy due to the force of attraction between two magnets

Question 9

What is nuclear energy?

Answer 9

Energy contained within the nucleus of an atom

Question 10

What is the law of conservation of energy?

Answer 10

Energy cannot be created or destroyed (only transferred)

Question 11

What is useful energy?

Answer 11

Energy transferred to where it is wanted and in the form it is wanted (e.g., sound from a TV)

Question 12

What is wasted energy?

Answer 12

Energy that is not usefully transferred (e.g., sound from an engine vibrating)

Question 13

Why can energy efficiency never be above 100%?

Answer 13

You can’t get more energy out of a system than is put in

Question 14

How can friction be prevented to avoid wasted energy?

Answer 14

Lubricating moving parts

Question 15

How can air resistance be reduced to minimize wasted energy?

Answer 15

Streamlining the shapes of moving objects

Question 16

How can sound be reduced to minimize wasted energy?

Answer 16

Tightening loose parts to avoid vibration

Question 17

How can the resistance of a wire be reduced to cut down on wasted energy?

Answer 17

Use a wire with little electrical resistance

Question 18

What is power?

Answer 18

The rate at which energy is transferred

Question 19

What is conduction?

Answer 19

When particles closer to a heat source vibrate faster, get warmer and transfer energy to neighbouring, cooler particles

Question 20

What is thermal conductivity?

Answer 20

The rate at which a material conducts thermal energy

Question 21

What are insulators?

Answer 21

Materials that have low thermal conductivity

Question 22

Why are metals good heat/electrical conductors?

Answer 22

They have delocalised electrons which are free to move between atoms and can carry charge

Question 23

How does thermal energy from the sun travel to Earth?

Answer 23

Infrared waves

Question 24

What is a perfect black body?

Answer 24

A theoretical object that absorbs all radiation that hits it

Question 25

What is specific heat capacity?

Answer 25

How much thermal energy is required to raise the temperature of 1 kg of a substance by 1 degree Celsius

Question 26

What is specific latent heat?

Answer 26

The amount of energy needed to change the state of 1 kg of substance without changing the temperature

Question 27

What is specific latent heat of fusion?

Answer 27

The amount of energy required to melt (or freeze) a substance at its melting point

Question 28

What is specific latent heat of vaporisation?

Answer 28

The amount of energy required to boil (or condense) 1 kg of substance at its boiling point

Question 29

How does loft insulation reduce the rate of energy transfer?

Answer 29

Fibreglass (which has a low thermal conductivity) has air trapped inside, which reduces the rate of energy transfer by conduction

Question 30

How does double glazing reduce the rate of energy transfer?

Answer 30

Air trapped between the 2 panes of glass acts as an insulator and reduces heat loss by conduction

Question 31

How does cavity wall insulation reduce energy transfer?

Answer 31

The space between 2 layers of brick is pumped with insulation (which is a better insulator than the air it replaces) reduces heat loss by conduction

Question 32

What are 3 advantages of fossil fuels as a source of energy?

Answer 32

* Cheap * Easy to find * Easy to transport

Question 33

What are 3 disadvantages of fossil fuels as a source of energy?

Answer 33

* Non-renewable: will run out eventually * Release atmospheric pollutants when burnt * Release sulfur dioxide, which causes acid rain

Question 34

What are 2 advantages of nuclear energy sources?

Answer 34

* Small amounts of fuel generate lots of energy * Does not give off atmospheric pollutants

Question 35

What are 2 disadvantages of nuclear energy sources?

Answer 35

* Non-renewable: will eventually run out * Nuclear waste is toxic and is expensive to be stored

Question 36

What is an advantage of biomass as an energy source?

Answer 36

Cheap and readily available; if replenished, it can be sustainable

Question 37

What are 2 disadvantages of biomass as an energy source?

Answer 37

* When burnt, gives off atmospheric pollutants * If crops aren't replenished, is not renewable

Question 38

What are 2 advantages of solar as an energy source?

Answer 38

* Potentially infinite supply * Singly dwellings can have their own electricity supply

Question 39

What are 2 disadvantages of solar as an energy source?

Answer 39

* Implementing solar panels can be expensive * Unreliable as weather must be sunny to generate energy

Question 40

What are 2 advantages of wind as an energy source?

Answer 40

* Potentially infinite supply * Does not release atmospheric pollutants

Question 41

What are 2 disadvantages of wind as an energy source?

Answer 41

* Implementing wind farms can be expensive * Wind farms cause visual and noise pollution

Question 42

What are 2 advantages of tidal as an energy source?

Answer 42

* Ideal for islands like the UK * Potentially infinite supply

Question 43

What are 2 disadvantages of tidal as an energy source?

Answer 43

* May have a negative impact on sealife * Tidal barrage construction is expensive

Question 44

How is geothermal energy generated?

Answer 44

Comes from energy released by radioactive substances deep within the earth, which is transferred by heating towards the earth's surface

Question 45

How does hydroelectricity generate energy?

Answer 45

Rainwater, collected in a reservoir, flows downhill. The flowing water drives turbines that turn electricity generators at the bottom of the hill