Energy

Question 1

what is the unit of force?

Answer 1

newtons

Question 2

what is the unit of energy?

Answer 2

joules

Question 3

what is the unit of distance?

Answer 3

metres

Question 4

what is the unit of mass?

Answer 4

kg

Question 5

what is the unit of strength of gravity?

Answer 5

newtons / kg

Question 6

what is the unit of height?

Answer 6

metres

Question 7

what is the principle of conservation of energy?

Answer 7

energy is never created or destroyed, only transferred between different energy stores

Question 8

what is a system?

Answer 8

object or group of objects that interact

Question 9

what is wasted energy?

Answer 9

energy dissipated to surroundings

Question 10

when work is done against frictional forces acting on an object, what happens to the temperature?

Answer 10

it rises

Question 11

what are the 8 energy stores?

Answer 11

• thermal (internal)
• kinetic
• gravitational potential
• elastic potential
• chemical
• magnetic
• electrostatic
• nuclear

Question 12

what is the thermal (internal) energy store?

Answer 12

the total kinetic and potential energy of the particles in an object/system

Question 13

what is the kinetic energy store?

Answer 13

energy of a moving object.

Question 14

what is the gravitational potential energy store?

Answer 14

energy of an object at height.

Question 15

what is the elastic potential energy store?

Answer 15

energy stored when an object is stretched or squashed.

Question 16

what is the chemical energy store?

Answer 16

energy stored in chemical bonds, such as those between molecules

Question 17

what is the magnetic energy store?

Answer 17

energy stored when repelling poles have been pushed closer together or when attracting poles have been pulled further apart.

Question 18

what is the electrostatic energy store?

Answer 18

energy stored when repelling charges have been moved closer together or when attracting charges have been pulled further apart.

Question 19

what is the nuclear energy store?

Answer 19

energy stored in the nucleus of an atom.

Question 20

what are the 4 energy transfer methods?

Answer 20

• mechanical work
• electrical work
• heating
• radiation

Question 21

what is mechanical work?

Answer 21

force moving an object through a distance

Question 22

what is electrical work?

Answer 22

charges moving due to a potential difference

Question 23

how does heating transfer energy?

Answer 23

due to temperature difference caused electrically or by chemical reaction

Question 24

how does radiation transfer energy?

Answer 24

energy transferred as a wave

Question 25

what is Specific heat capacity?

Answer 25

the energy needed to increase the temperature of 1kg of a substance by 1 degree celsius

Question 26

describe the process of conduction

Answer 26

- energy makes the ions in the rod vibrate faster - as ions in the solid metal are close together, this increased vibration means that they collide with neighbouring ions more frequently - energy is passed on through the metal by these collisions, transmitting the energy - more frequent collisions increase the rate of transfer.

Question 27

what are renewable energy resources?

Answer 27

resources that can be replenished as they are used

Question 28

what is a a non-renewable energy resource?

Answer 28

a resource which cannot be replenished

Question 29

what are 2 non-renewable energy resources?

Answer 29

- fossil fuels - nuclear fuel

Question 30

what energy store are fossil fuels?

Answer 30

chemical

Question 31

what energy store is nuclear fuel?

Answer 31

nuclear

Question 32

what are 2 advantages of using fossil fuels?

Answer 32

- very reliable - high power output

Question 33

what is a disadvantage of using fossil fuels?

Answer 33

releases CO2

Question 34

what are 2 advantages of using nuclear fuel?

Answer 34

- very reliable - very high power output

Question 35

what is a disadvantage of using nuclear fuel?

Answer 35

dangerous radioactive waste

Question 36

list as many renewable energy sources as you can.

Answer 36

- biofuel - wind - hydroelectricity - geothermal - tidal - solar - water waves

Question 37

what energy store does biofuel use?

Answer 37

chemical

Question 38

what are 3 advantages of using biofuel?

Answer 38

- reliable - medium power output - low negative impact - carbon neutral

Question 39

what energy store does wind power use?

Answer 39

kinetic

Question 40

what are 4 disadvantages of wind power?

Answer 40

- unreliable as it depends on weather - low power output - take up large areas of land - birds can be killed

Question 41

what energy store does hydroelectricity use?

Answer 41

gravitational potential

Question 42

what are 2 advantages of hydroelectricity?

Answer 42

- very reliable - medium power output

Question 43

what is a disadvantage of hydroelectricity?

Answer 43

big areas must be flooded to build dams

Question 44

what energy store does geothermal use?

Answer 44

thermal

Question 45

what are 3 advantages of geothermal energy?

Answer 45

- reliable - medium power output - very low negative impact

Question 46

what is a disadvantage of geothermal energy?

Answer 46

not available everywhere

Question 47

what is the energy store of tidal energy?

Answer 47

kinetic

Question 48

what are 2 advantages of using tidal energy?

Answer 48

- very reliable - very high power output

Question 49

what are 2 disadvantages of using tidal energy?

Answer 49

- hard to harness - tidal barrages can negatively affect birds feeding on mud flats

Question 50

what energy store does solar energy use?

Answer 50

nuclear

Question 51

what is an advantage of solar energy?

Answer 51

low negative impact

Question 52

what are 3 disadvantages of solar energy?

Answer 52

- very unreliable as dependent on weather - low power output - large areas necessary

Question 53

what energy store do water waves use?

Answer 53

kinetic

Question 54

what are 2 disadvantages of using water waves for energy?

Answer 54

- unreliable as weather dependent - low power output

Question 55

what is an advantage of using water waves for energy?

Answer 55

very low negative impact

Question 56

what does 'doing work' on a system do?

Answer 56

increases the energy stored in a system

Question 57

what can unwanted energy transfers be reduced by?

Answer 57

- lubrication - tightening any loose parts - thermal insulation

Question 58

how does lubrication reduce unwanted energy transfers?

Answer 58

reduces the friction that produces heat

Question 59

how does tightening loose parts reduce unwanted energy transfers?

Answer 59

prevents unwanted vibration that wastes energy as sound

Question 60

how does thermal insulation reduce unwanted energy transfers?

Answer 60

reduces heat loss