energy topic

Question 1

name all the energy stores

Answer 1

• thermal energy
• kinetic energy
• gravitational potential
• elastic potential
• chemical energy
• magnetic energy
• electrostatic energy
• nuclear energy

Question 2

what is energy measured in?

Answer 2

Joules(J)

Question 3

gravitational potential energy

Answer 3

mass x gravity x height

Question 4

kinetic energey

Answer 4

0.5 x mass x (velocity)^2

Question 5

elastic potential energy

Answer 5

0.5 x spring constant x (extension)^2

Question 6

hook’s law

Answer 6

the force required to stretch an elastic object such as a metal spring is directly proportional to the extension of the spring.

Question 7

work done

Answer 7

force x distance

Question 8

power

Answer 8

the rate at which energy is transfered

Question 9

efficiency def

Answer 9

a measure of how much energy is transferred usefully in a system

Question 10

efficiency equ

Answer 10

useful energy output/ total energy input
or
useful power output/ total power input

Question 11

what is solar power

Answer 11

works by converting light from the sun into electricity

Question 12

solar power advantages

Answer 12

• pollution free and emits no green house gases
• reduces dependence on fossil fuels
• virtually no maintenance
• can be installed anywhere

Question 13

solar power disadvantages

Answer 13

• needs a lot of space
• on cloudy days they produce little energy
• lower production in winter months
• usually used to produce energy on a small scale

Question 14

solar power price

Answer 14

initial cost is high but after that the energy is free and running cost is almost nil

Question 15

what is geothermal power

Answer 15

uses energy from underground thermal energy stores

Question 16

geothermal advantages

Answer 16

• reliable with very few environmental problems
• 30%-60% savings on heating and 25%-50% savings on cooking

Question 17

geothermal disadvantage

Answer 17

• only possible in volcanic areas
• large scale geothermal power plants are dangerous to the earths surface
• the amount to build is high compared to the energy produces

Question 18

how does geothermal energy work

Answer 18

cold water is pumped down deep into the ground where it turns into steam. then the steam in pumped back up into turbines that generate electricity

Question 19

what is hydroelectric power

Answer 19

is a dorm of energy that harnesses the power of water in motion

Question 20

how does hydroelectric power work

Answer 20

at hydropower plants water flows through a pipe, or penstock( controlling or directing the flow of water), then pushes against and turns blades in a turbine to spin a generator to produce electricity

Question 21

hydroelectric power advantages

Answer 21

• it can provide immediate response to increase demand for electricity
• there is no problem with reliability except for in times of a drought

Question 22

hydroelectric power disadvantages

Answer 22

• it von disrupt wildlife habitat

Question 23

hydroelectric costs

Answer 23

initial costs are high, but there are no fuel costs and minimal running costs

Question 24

how does wind power work

Answer 24

each turbine has a generator inside it. the rotating blades turn the generator to produce energy

Question 25

wind power advantages

Answer 25

- there is no pollution except when they are manufactured - it is cost effective - no permanent damage to landscape

Question 26

wind power disadvantages

Answer 26

- they can be very noisy - it would take 1500 wind turbines to replace one coal fuel power station - ugly

Question 27

wind power costs

Answer 27

the initial costs are quite high but there are no fuel costs and minimal running costs

Question 28

what is wave power

Answer 28

is where air is forced into a generator by the waves

Question 29

wave power advantages

Answer 29

- there is no pollution

Question 30

wave power disadvantages

Answer 30

- disturbing sea bed and ruining habitats - fairy unreliable since waves tend to die out when wind drops

Question 31

wave power costs

Answer 31

the initial costs are high but there are no fuel costs and minimal running costs

Question 32

what is tidal energy

Answer 32

tides are used lots of ways to generate electricity. the most common being tidal barrage

Question 33

was is a tidal barrage

Answer 33

is a big do

Question 34

tidal energy advantages

Answer 34

- there is no pollution - the tides are pretty reliable in the sense they will happen twice a day without fail

Question 35

tidal energy disadvantages

Answer 35

- they prevent free access by boats - spoil view - alter habitats

Question 36

tidal energy costs

Answer 36

initial costs are moderate, high but there are no fuel costs and minimal running costs

Question 37

what is biofuel

Answer 37

is any fuel that is derived from biomass

Question 38

biofuel advantages

Answer 38

- efficient fuel - it is easy to source - reduces dependence on foreign aid

Question 39

biofuel disadvantages

Answer 39

- industrial pollution - shortage of food

Question 40

biofuel costs

Answer 40

quite expensive

Question 41

conduction

Answer 41

the process where vibrating particles transfer energy to neighbouring particles

Question 42

convection

Answer 42

is where energetic particles move away from hotter to cooler regions

Question 43

specific heat capacity

Answer 43

the amount of energy required to raise 1Kg of a substance by 1 degree C

Question 44

change in thermal energy

Answer 44

mass x specific heat capacity x temp change

Question 45

density

Answer 45

mass/volume

Question 46

thermal energy store

Answer 46

the total energy of an object due to the kinetic energy of its atoms and/or molecules depending on its mass

Question 47

temperature

Answer 47

a measure of the average kinetic energy of molecules

Question 48

specific latent heat of fusion

Answer 48

is the energy required to convert 1kg of a substance from a solid to a liquid or from liquid to solid without a change in temperature

Question 49

specific latent heat of vaporisation

Answer 49

is the energy required to convert 1kg of a substance from liquid to gas or vies versa without changing the temperature

Question 50

latent heat

Answer 50

energy/mass