Energy

Question 1

Chemical energy

Answer 1

Energy is transferred when chemical reactions take place, the energy stored in fuels

Question 2

Electrical energy

Answer 2

Energy transferred by an electrical current

Question 3

Elastic potential energy

Answer 3

Energy stored in a springy object

Question 4

Elastic potential energy formula

Answer 4

½ x spring constant x extension²

½ x k x e²

K = spring constant (newtons per metre, N/m)

Question 5

Kinetic energy

Answer 5

The energy of a moving object

Question 6

Kinetic energy formula

Answer 6

½ x mass x velocity²

½ x m x v²

Question 7

Gravitational potential energy

Answer 7

The energy of an object due to its position

Question 8

Gravitational potential energy formula

Answer 8

Mass x gravitational field strength x height

m x g x h

Question 9

Conservation of energy

Answer 9

Energy cannot be created or destroyed, can only be changed from one form to another

Question 10

Work done

Answer 10

Energy is transferred from one store to another

Question 11

Work done formula

Answer 11

Force x distance

F x D

Question 12

Power

Answer 12

Rate of doing work

Question 13

Power formula

Answer 13

Energy / time

E / T

Question 14

Wasted energy

Answer 14

Dissipated into surroundings in the form of heat

Question 15

How can energy be transferred?

Answer 15

Mechanically - work is done by force

Electrically - work is done by moving charges

Heating - conduction and convection

Question 16

Specific heat capacity practical

Answer 16

Place the immersion heater into the central hole at the top of the block

Place the thermometer into the smaller hole and put a couple of drops of water into the hole to make sure the thermometer is surrounded by hot material

Fully insulate the block by wrapping it loosely with materials

Record the temperature of the block

Connect the heater to the power supply and turn it off after ten minutes

Question 17

Specific heat capacity formula

Answer 17

Change in thermal energy / mass x temperature change

ΔJ / m x ΔT

M = mass (kilogram, kg)

ΔJ = change in thermal energy (joules, J)

ΔT = temperature change (celsius, °C)

Question 18

Efficiency

Answer 18

A measure of how well an object outputs useful energy, compared to how much energy is taken in

Question 19

Efficiency formula

Answer 19

Useful power output / total power input

Question 20

Fossil fuels (non-renewable)

Answer 20

Oil, coal, natural gas

High power output

Releases CO2

Question 21

Nuclear fuels (non-renewable)

Answer 21

Very high power output

Radioactive waste is hard to store

Question 22

Biofuel (renewable)

Answer 22

Medium power output

Carbon neutral - no effect on the environment

Takes up space for farming

Question 23

Wind (renewable)

Answer 23

Very low power output

Takes up large areas that can be used for farming and is an eye saw

Question 24

Hydroelectricity (renewable)

Answer 24

Medium power output

Local residents are affected by noise pollution

Question 25

Geothermal (renewable)

Answer 25

Medium power output Very low impact on the environment

Question 26

Sun (renewable)

Answer 26

Fluctuating power output Depends on the weather

Question 27

Burning fossil fuel process

Answer 27

The fossil fuel is burnt to boil H2O and turn it into steam The steam turns the turbines The turbines spin powering the generator Step-up transformers increase the voltage and connect this to the National Grid Step-down transformers decrease the voltage before feeding it to homes

Question 28

Nuclear power stations

Answer 28

Nuclear uranium fuel rods heat water The water turns into steam in the boiler The steam turns the turbine The turbine powers the generator which creates electricity The electricity is sent through transformers which are sent to homes

Question 29

Nuclear fission process

Answer 29

Neutron hits the uranium nucleus Uranium nucleus splits into smaller nuclei and some more neutrons These neutrons hits more uranium nuclei and the process continues

Question 30

Wind turbines

Answer 30

Wind turns a turbine Turbine powers a generator Generator creates energy

Question 31

Solar cells

Answer 31

The solar panel absorbs the sunlight The panel converts sunlight to DC current

Question 32

Hydroelectric

Answer 32

Water is held behind a dam in a reservoir high up a mountain Rainfall fills the reservoir When energy is needed, the water is allowed to run down through pipes to another reservoir lower down the mountain As the water runs through the pipes it spins turbines that are linked to generators The water can be pumped back up during the night when electricity is cheaper

Question 33

Tidal barrages

Answer 33

The barrage gates close, trapping water as the tide rises As the tide falls, water is released through turbines in the barrage, generating electricity from the moving water During low tide, water flows back into the estuary as the tide rises again, potentially generating additional power

Question 34

Geothermal

Answer 34

Heat and steam generated from volcanoes are extracted The steam or hot water is used to drive turbines connected to generators, producing electricity The cooled water is often re-injected into the ground to sustain the reservoir

Question 35

Biofuel

Answer 35

Organic matter like crops or waste is harvested Biomass is processed into biofuels, such as ethanol or biodiesel The biofuels are used as an alternative to fossil fuels in vehicles, electricity generation, or heating

Question 36

Carbon capture

Answer 36

When carbon is captured and stored underground