energy

Question 1

specific heat capacity variables

Answer 1

independant-material
dependant- specific heat capacity
control- insulating layer, initial temp, time taken

Question 2

specific heat capacity method

Answer 2

1. using the balance, measure and record the mass of the copper block in kg.
2. wrap insulation around the block.
3. put the heater into a large hole in the block and the block onto the heatproof mat.
4. connect the power pack and ammeter in series and the voltmeter across the power pack .
   5.using the pipette put a drop of water into the small hole.
5. put the thermometer into the small hole and measure the temp.
6. switch the power pack to 12v and turn it on.
7. read and record the voltmeter and ammeter readings-during the experiment, they shouldn’t change.
8. turn on the stop clock and record the temp every min for 10 min.
9. record results in a table.
10. calculate work done and plot a line graph of work done against temp.

Question 3

kinetic energy equation

Answer 3

Ek=1/2mv2

kinetic energy=1/2xmassxspeed2

Question 4

gravitational potential energy equation

Answer 4

Ep=mgh

gravitational potential energy=mass x gravitational field strength x height

Question 5

what happens when an object falls

Answer 5

it looses gravitational energy and gains kinetic energy

Question 6

elastic potential energy equation

Answer 6

elastic potential energy=1/2x spring constant x extention2

E=1/2Ke2

Question 7

change in thermal energy equation

Answer 7

change in thermal energy= mass x specific heat capacity x temp

Question 8

what is specific heat capacity

Answer 8

amount of energy needded to raise the temp of 1kg of a material by 1c

Question 9

kinetic energy store

Answer 9

moving objects have kinetic energy

Question 10

thermal energy store

Answer 10

all objects have thermal energy

Question 11

chemical energy store

Answer 11

anything that can release energy during a chemical reaction

Question 12

elastic potential energy store

Answer 12

things that are streched

Question 13

gravitational potential energy store

Answer 13

anything that is raised

Question 14

electrostatic energy store

Answer 14

charges that attract or repel

Question 15

magnetic

Answer 15

magnets attract or repel

Question 16

nuclear

Answer 16

the nucleus of an atom releases energy

Question 17

how can energy be transfered in
mechanically,electrically,heating

Answer 17

1.when work is done
2.when moving charge does not work
3.when energy is transferred from a hotter object to a colder object

Question 18

conservation of energy

Answer 18

energy that can never be created or destroyed, just transferred from one form to another. Some energy is transferred usefully and some energy gets transferred into the environment. this is mostly wasted energy

Question 19

what is power

Answer 19

rate of transfer of energy- amount of work done in a given time

Question 20

power equation

Answer 20

power=energy tarnsfered divided by time

p(w)= e(j) divided by t(s)

Question 21

power work equaion

Answer 21

power= work divide by time

Question 22

how does lubrication reduce the amount of friction

Answer 22

when and object moves there are frictional forces acting some energy is lost into the environment e.g oil

Question 23

conduction

Answer 23

when a soil is being heated the particles vibrate and collide more and the energy is transferred.

Question 24

convection

Answer 24

when a liquid or gas is being heated the particles move faster. this means the liquid or gas becomes less dense the denser the region will rise above the cooler region this is a convection current

Question 25

insulation

Answer 25

reduces the amount of heat loss in your home

Question 26

insulation examples

Answer 26

thick walls thermal insulation(reducing convection) cavity walls (reducing convection and conduction) double glazing (reduces conduction)

Question 27

efficiency meaning

Answer 27

when energy is transferred some energy is wasted the less energy that is waste during the transfer the more efficient the transfer

Question 28

two equations for efficiency

Answer 28

1. efficiency = usefull output energy transfer/ total input energy transfer 2. efficiency=usefull power output/total power input

Question 29

non renewable

Answer 29

coal , oil, gas, they will all run out they damage the environment but provide most of the energy we have

Question 30

renewable

Answer 30

they will never run out can be unreliable and do not provide as much energy as non renewable

Question 31

solar advantage

Answer 31

renewable , no pollution, sunny countries its reliable

Question 32

solar disadvantage

Answer 32

lots of energy needed to build only works during the day cannot increase power if needed

Question 33

geothermal advantage

Answer 33

renewable and reliable as the rocks are always hot power stations have very small impact on environment

Question 34

geo thermal disadvantage

Answer 34

may release green house gasses and only found in specific places

Question 35

wind advantage

Answer 35

renewable, no pollution, no lasting damage to environment, minimal running cost

Question 36

wind disadvantage

Answer 36

not as reliable do not work when their is no wind cannot increase supply when needed

Question 37

hydroelectric advantage

Answer 37

renewable, no pollution can increase supply if needed

Question 38

hydroelectric disadvantage

Answer 38

bif impact on environment, animals and plants may loose their habitat

Question 39

wave power advantage

Answer 39

renewable no pollution

Question 40

wave power disadvantage

Answer 40

disturbes the seabed and habitat of animals unreliable

Question 41

tidal barrages advantage

Answer 41

renewable very reliable no pollution

Question 42

tidal barages disadvantage

Answer 42

changes habitat of wildlife fish can be killed in the turbines

Question 43

biofuels advantage

Answer 43

renewable, reliable, carbon neutral

Question 44

biofuels disadvantage

Answer 44

highcost, growing biofuels may cause a problem with regards to space,clearance of natural forrests

Question 45

non-renewable - fossil fuels advantage

Answer 45

reliable enough to meet current demand can producemore energy when their is more demand

Question 46

non-renewable- fossil fuels disadvantage

Answer 46

e running out, releases co2 leading to global warming releases so2 which causes acid rain