conservation of energy - topic 2

Question 1

what is kinetic energy

Answer 1

anything moving has kinetic energy

Question 2

what is thermal energy

Answer 2

any object but the hotter it is the more thermal energy it has

Question 3

what is chemical energy

Answer 3

anything that can release energy by a chemical reaction, such as energy stored in batteries

Question 4

what is gravitational potential energy

Answer 4

Height

Question 5

what is elastic potential energy

Answer 5

anything that is stretched or compressed

Question 6

what is electrostatic energy

Answer 6

anything with electric charge that is interacting with another electric charge

Question 7

what it magnetic energy

Answer 7

anything magnetic that is interacting with another magnet

Question 8

what are the 4 ways energy can be transferred between stores

Answer 8

mechanically, be heating , electrically and by radiation

Question 9

mechanical

Answer 9

pushing and pulling

Question 10

what is electrical energy

Answer 10

charges moving around a circuit

Question 11

what is work done

Answer 11

way of saying energy transferred

Question 12

what is the conservation of energy principle

Answer 12

energy can be transferred usefully, stored or dissipated but never created or dissipated

Question 13

what is the equation for total energy input

Answer 13

useful energy output + wasted energy

Question 14

what is the equation for kinetic energy

Answer 14

1/2 x mass x velocity^2

Question 15

what is the equation for change in GPE

Answer 15

mass x gravitational field strength x change in vertical height

Question 16

how to reduce amount of energy lost from buildings using thermal insulators

Answer 16

cavity walls
double glazing
loft insulation
hot water tank jacket

Question 17

what are lubricants used for

Answer 17

reducing friction between two surfaces when the move

Question 18

what is the equation for efficiency

Answer 18

useful energy transferred / total energy transferred

Question 19

what are the 4 non renewable energy sources

Answer 19

coal
oil
natural gas
nuclear fuels

Question 20

what are the 5 renewable energy sources

Answer 20

wind
tides
sun 
hydroelectricity
bio-fuel

Question 21

uses of petrol

Answer 21

powers lots of vehicles

Question 22

uses of coal

Answer 22

heating, old fashioned steam trains

Question 23

uses of oil

Answer 23

heating homes

Question 24

uses of natural gas

Answer 24

radiators which are used for heating homes

Question 25

pros of wind power

Answer 25

no pollution

Question 26

cons of wind power

Answer 26

very noisy high initial cost not reliable spoil the view

Question 27

pros of solar cells

Answer 27

no pollution | reliable in very sunny countries

Question 28

cons of solar cells

Answer 28

high initial costs need a lot energy to manufacture only generate electricity during the day and not at night

Question 29

pros of hydro-electricity power stations

Answer 29

no pollution reliable except in a drought provide immediate response to increasing demand for electricity

Question 30

cons of hydro-electricity power stations

Answer 30

flooding habitats destroyed vegetation destroyed high initial costs

Question 31

pros of tidal barrages

Answer 31

no pollution | reliable

Question 32

cons of tidal barrages

Answer 32

spoil the view alter habitat of wildlife high initial cost

Question 33

pros of bio-fuel

Answer 33

reliable | carbon neutral

Question 34

cons of bio-fuel

Answer 34

high refinery costs produce carbon dioxide when burned take up space for growing crops takes long to grow crops

Question 35

how do cavity walls and double glazing remove unwanted energy transfers

Answer 35

they both an inner and outer wall/ sheets of glass with an air gap in the middle which reduces the amount of energy transferred by conduction through walls or windows

Question 36

how can you improve efficiency

Answer 36

decreasing amount of wasted energy and making sure more of the supplied energy goes to the useful stores by lubrication or thermal insulation

Question 37

how does wind generate electricity

Answer 37

a wind turbine has a generator inside it which generates electricity when wind turns the blades which turns the generator

Question 38

how does the sun generate electricity

Answer 38

solar cells generate electric currents directly from the sun's radiation and so can be used to charge batteries that can power electrical devices

Question 39

how do bio-fuels generate electricity

Answer 39

they are burned to heat water, which produces steam which drives a turbine, which drives a generator and generates electricity