p1

Question 1

name the eight energy stores

Answer 1

1. kinetic
2. thermal
3. gravitational potential
4. magnetic
5. elastic
6. chemical
7. electrostatic
8. nuclear

Question 2

what is meant by a system?

Answer 2

• an object or a group of objects

Question 3

when a system changes - what happens?

Answer 3

• energy is transferred

Question 4

what is a closed system?

Answer 4

• when energy or matter cannot enter or leave

Question 5

how is energy transferred when throwing a ball in the air?

Answer 5

chemical to kinetic

Question 6

how is energy transferred when dropping a ball?

Answer 6

gravitational to kinetic

Question 7

how is energy transferred when a car breaks?

Answer 7

kinetic to thermal

Question 8

how is energy transferred during a collision between a moving and stationary object?

Answer 8

kinetic to elastic and thermal

Question 9

what is specific heat capacity?

Answer 9

• the amount of energy required to raise the temperature of 1kg of the substance by 1 degrees

Question 10

what is the conservation of energy principle?

Answer 10

• energy can be transferred, stored or dissipated but it cannot be created or destroyed.

Question 11

what is meant by dissipated energy?

Answer 11

• energy that is wasted or lost during a reaction

Question 12

what is power?

Answer 12

• the rate at which energy is transferred (work done).

Question 13

what is the unit of power?

Answer 13

• watts

Question 14

name the two equations used to calculate power

Answer 14

• power = energy transferred/time
• power = work done/time

Question 15

describe the energy transfer in the pendulum (the weight hung)

Answer 15

• when the ball goes up, it has maximum gravitational energy.
• when it goes to the bottom, it has maximum kinetic energy.
• energy is transferred to gravitational energy to kinetic back to gravitational energy.

Question 16

• how can lubrication reduce frictional forces?

Answer 16

• a thin layer is formed so two surfaces don’t rub against each other.

Question 17

what is conduction?

Answer 17

• how thermal energy travels through solids.

Question 18

what is convection?

Answer 18

• when particles with lots of heat energy replace particles with less heat energy.

Question 19

how can you reduce heat loss in a house?

Answer 19

1. cavity walls
   - the air gap reduces the amount of energy lost
   - reduces energy transfer by convection
2. double-glazed windows
   - they trap the heat
   - they have an air gap between two glasses, which prevents energy transfer by conduction.
3. loft insulation
   - reduces convection currents

Question 20

what is efficiency?

Answer 20

• efficiency tells us what fraction of energy we put into an appliance is transferred to useful energy.

Question 22

what is meant by non-renewable resources?

Answer 22

• a resource that cannot be replace once used.

Question 23

name three non-renewable resources

Answer 23

1. coal
2. oil
3. gas

Question 24

state the advantages and disadvantages of non-renewable resources

Answer 24

advantages =
- reliable
- releases lots of energy
- cheap
disadvantages =
- releases lots of CO2
- it will run out
- burning fossil fuels can release pollutants

Question 25

what is meant by renewable resources?

Answer 25

- a source that can be replenished as it is used

Question 26

name seven renewable energy resources

Answer 26

1. wind power 2. solar power 3. geothermal 4. wave power 5. hydroelectric power 6. tidal power 7. biofuels

Question 27

how do wind turbines work?

Answer 27

- they use wind to generate electricity. - the wind turns the blades of a turbine around a rotor, which spins a generator and creates electricity.

Question 28

state the advantages of using wind turbines to generate electricity

Answer 28

- useful when the weather is windy. - does not release co2

Question 29

state the disadvantages of using wind turbines to generate electricity

Answer 29

- wind power does not work when it is not windy - spoils the view - unreliable

Question 30

how do solar cells work?

Answer 30

- they use sunlight to generate electricity

Question 31

state the advantages of using solar cells to generate electricity

Answer 31

- renewable - no pollution

Question 32

state the disadvantages of using solar cells to generate electricity

Answer 32

- they do not work on cloudy days - expensive

Question 33

how does geothermal work?

Answer 33

- they use steam to produce electricity

Question 34

state the advantages of using geothermal to generate electricity

Answer 34

- always available - renewable - silent energy

Question 35

state the disadvantages of using geothermal to generate electricity

Answer 35

- requires specific locations - expensive - generates waste

Question 36

how do tidal barrages work?

Answer 36

- they use kinetic energy from the tide coming in, through a turbine, to generate electricity.

Question 37

state the advantages of using tidal barrages to generate electricity

Answer 37

- reliable - energy efficient - no pollution

Question 38

state the disadvantages of using tidal barrages to generate electricity

Answer 38

- environmental impact (could be harmful to the wildlife) - expensive - requires specific location

Question 39

how does hydroelectric power work?

Answer 39

- dam is built so water can flow through. - they use kinetic energy to turn a turbine and generate electricity.

Question 40

state the advantages of using hydroelectric power to generate electricity

Answer 40

- no pollution - produces lots of energy

Question 41

state the disadvantages of using hydroelectric power to generate electricity

Answer 41

- habitats are destroyed (when dams are built) - expensive

Question 42

how does wave power work?

Answer 42

- wave machines use the kinetic energy in waves to drive electricity generators.

Question 42

state the advantages of using wave power to generate electricity

Answer 42

- reliable - no pollution

Question 43

state the disadvantages of using wave power to generate electricity

Answer 43

- expensive - requires specific location

Question 44

what is biofuel made from?

Answer 44

- plant materials

Question 45

what kind of energy is biofuel?

Answer 45

- renewable

Question 46

state the advantages of using biofuel

Answer 46

- no pollution

Question 47

state the disadvantages of using biofuel

Answer 47

- if land is used to grow crops for fuel, that could increase the price of food. - species lose habitat