Energy Resources and Energy Transfers

Question 1

State the nine types of energy

Answer 1

electrical 
light
sound
kinetic
nuclear 
thermal/heat
gravitational potential 
elastic potential 
chemical

Question 2

State the principle of the conservation of energy

Answer 2

energy can never be created nor destroyed, its only ever transferred from one form to another

Question 3

When is energy only useful ?

Answer 3

when it can be transferred from one form to another

Question 4

efficiency =

Answer 4

useful energy output / total energy input

Question 5

State the meaning of dissipate

Answer 5

spread out and lost

Question 6

Can a device be 100% efficient?

Answer 6

no, wasted energy is always dissipated as heat

Question 7

from the entire energy output into a machine, how much usually becomes heat?

Answer 7

by the end, all of it, both useful and wasted, as it gets transferred to cooler surroundings it dissipates though

Question 8

what is the measurement of all energy ?

Answer 8

Jules J

Question 9

Electrical devices convert electrical energy into…

Answer 9

sound light (and wasted heat)

Question 10

Batteries convert chemical energy into…

Answer 10

electrical to run electric devices (and wasted heat)

Question 11

Gravitational and elastic potential energy always convert into…

Answer 11

kinetic energy first (and wasted heat)

Question 12

what is radiation?

Answer 12

transfer of heat by electromagnetic waves which occurs in solids, liquids and gases

Question 13

what is conduction?

Answer 13

the process where vibrating particles pass on extra kinetic energy to neighbouring particles

Question 14

what is convection?

Answer 14

process where more energetic particles move up (less dense) to cooler regions, bringing their heat with them

Question 15

loft insulation

Answer 15

layer of fibreglass wool across loft floor and ceiling to reduce convection and conduction

Question 16

hot water tank jacket

Answer 16

fibre glass wool covering tank to reduce convection and conduction

Question 17

double glazing

Answer 17

two layers of glass with an air gap reduces conduction and convection

Question 18

draught-proofing

Answer 18

strips of foam around doors / windows to reduce convection

Question 19

cavity wall insulation

Answer 19

foam between bricks prevents convection

air in foam prevents conduction

Question 20

work done =

Answer 20

force x distance

Question 21

power =

Answer 21

work done / time

Question 22

measurement for power

Answer 22

watts

Question 23

kinetic energy =

Answer 23

0.5 x mass x velocity²

Question 24

gravitational potential energy =

Answer 24

mass x height x gravity

Question 25

when falling, kinetic energy gained is the same as...

Answer 25

GPE lost

Question 26

name the advantages of fossil fuels

Answer 26

releases lots of energy relatively cheap reliable (doesn't need weather) already have lots of stations

Question 27

name the disadvantages of fossil fuels

Answer 27

``` carbon dioxide (global warming) sulfur dioxide (acid rain) THEY WILL RUN OUT ```

Question 28

how do nuclear reactors work?

Answer 28

use nuclear fission of uranium, which produces heat, heating water to produce steam which turns a turbine

Question 29

advantages of nuclear reactors

Answer 29

doesn't produce green house gases | lots of uranium avaliable

Question 30

advantages of wind farms

Answer 30

cheap to maintain | renewable

Question 31

advantages of geothermal energy

Answer 31

cheap to maintain | renewable

Question 32

disadvantages of nuclear reactors

Answer 32

expensive to build/maintain long start up processing uranium causes pollution produces radioactive waste

Question 33

disadvantages of wind farms

Answer 33

rather expensive to build low energy level unreliable (needs wind)

Question 34

disadvantages of geothermal energy

Answer 34

cost of drilling down is expensive | high build cost

Question 35

how do wind farms work?

Answer 35

wind turns blades, which turns a generator

Question 36

how does geothermal energy work?

Answer 36

water pumped down to hot rocks where it is heated and comes back up as steam to turn a turbine

Question 37

how do solar cells work ?

Answer 37

transform light directly into electrical energy | direct current produced

Question 38

advantages of solar cells

Answer 38

renewable no pollution free to maintain

Question 39

disadvantages of solar cells

Answer 39

expensive to build | don't work at night (however can be linked with a chargeable battery)

Question 40

what are solar panels ?

Answer 40

black water pipes inside a glass box which lets heat and light in from the sun and heats the water

Question 41

how can you cook with solar power ?

Answer 41

use a curved mirror to focus the suns light and heat onto the food these are slow, bulky and unreliable however

Question 42

how does wave power work ?

Answer 42

using lots of small wave converters located around the coast which move with the waves and drive a generator

Question 43

advantages/disadvantages of wave power

Answer 43

no pollution and renewable initial costs are high fairly unreliable spoil the view and hazard to boats

Question 44

how do tidal barrages work ?

Answer 44

big dams build across river estuaries with turbines in them | as the tide comes in it fills the estuary and can be allowed through turbines

Question 45

advantages/disadvantages of tidal barrages

Answer 45

no pollution and renewable and cheap to maintain | high build cost, alters habitats and prevents boat free access

Question 46

how does hydroelectricity work ?

Answer 46

requires a flooded valley (use a dam) rainwater caught and allowed through turbines gravitational potential - kinetic

Question 47

advantages of hydroelectricity

Answer 47

``` renewable and cheap to maintain no pollution immediate response (can release all water) ```

Question 48

disadvantages of hydroelectricity

Answer 48

causes rotting vegetation (releases methane and carbon dioxide) high initial costs risk of drought

Question 49

what is pumped storage ?

Answer 49

pumping water back up to a higher reservoir in moments of low demand to 'store' energy that has already been generated