conservation of energy

Question 1

eight main stores of energy

Answer 1

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

Question 2

Magnetic energy store

Answer 2

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

Question 3

Internal (thermal) energy store

Answer 3

The total kinetic and potential energy of the particles in an object, in most cases this is the vibrations – also known as the kinetic energy – of particles. In hotter objects, the particles have more internal energy and vibrate faster.

Question 4

Chemical energy store

Answer 4

The energy stored in chemical bonds, such as those between molecules.

Question 5

Kinetic energy store

Answer 5

The energy of a moving object.

Question 6

Electrostatic energy store

Answer 6

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

Question 7

Elastic potential energy store

Answer 7

The energy stored when an object is stretched or squashed.

Question 8

Gravitational potential energy store

Answer 8

The energy of an object at height.

Question 9

Nuclear energy store

Answer 9

The energy stored in the nucleus of an atom.

Question 10

four main ways of transferring energy

Answer 10

mechanical work - a force moving an object through a distance
electrical work - charges moving due to a potential difference
heating - due to temperature difference caused electrically or by chemical reaction
radiation - energy transferred as a wave, eg light and infrared - the Sun emits light radiation and infrared radiation

Question 11

enegry big law

Answer 11

Energy can be transferred usefully, stored or dissipated, but it cannot be created or destroyed.

Question 11

calculation with change in GPE, m, g, change in h

Answer 11

change in GPE = m x g x change in h

Question 12

GPE units

Answer 12

joules

Question 13

m units

Answer 13

kg

Question 14

calculation with KE, m + v

Answer 14

KE = 1/2 x m x v^2

Question 15

efficiency calculation

Answer 15

efficiency = useful energy transferred/ total energy supplied

Question 16

How might a toy car be made more efficient?

Answer 16

add oil to moving parts

Question 17

What is a good thermal conductor?

Answer 17

A material that easily allows thermal energy through

Question 18

What is the best insulator?

Answer 18

air

Question 19

Why is loft insulation so effective?

Answer 19

It traps air, which is a good insulator and reduces the heat lost from the home

Question 20

Why is energy wasted when surfaces rub together in a device?

Answer 20

Internal (thermal) energy of the surfaces increases, and this is then transferred to the surroundings

Question 21

what are energy resources + examples

Answer 21

-systems that can store large amounts of energy
-fossil fuels, nuclear fuel, biofuel, wind, etc

Question 22

Renewable resources are replenished either by:

Answer 22

-human action,eg trees cut down for biofuel are replaced by planting new trees
-natural processes, eg water let through a dam for hydroelectricity is replaced through the water cycle

Question 23

9 types of energy resources

Answer 23

Fossil fuels (oil, coal and natural gases)
Nuclear fuels
Biofuel
Wind
Hydroelectricity
Geothermal
Tides
Sun
Water waves

Question 24

Fossil fuels: Energy store, Renewable or non-renewable, Uses, Power output, Impact on environment

Answer 24

-Chemical -Non-renewable -Transport, heating, electricity generation -High -Releases CO2 (causes global warming)

Question 25

Nuclear fuels: Energy store, Renewable or non-renewable, Uses, Power output, Impact on environment

Answer 25

-Nuclear -Non-renewable -Electricity generation -Very high -Radioactive waste (needs to be disposed of safely)

Question 26

Biofuel: Energy store, Renewable or non-renewable, Uses, Power output, Impact on environment

Answer 26

-Chemical -Renewable -Transport, heating, electricity generation -Medium -Carbon-neutral so low impact

Question 27

Wind: Energy store, Renewable or non-renewable, Uses, Power output, Impact on environment

Answer 27

-Kinetic -Renewable -Electricity generation -Very low -Take up large areas that could be used for farming, people say windmills spoil their view

Question 28

Hydroelectricity: Energy store, Renewable or non-renewable, Uses, Power output, Impact on environment

Answer 28

-Gravitational potential -Renewable -Electricity generation -Medium -Local habitats are affected by the large areas that need to be flooded to build dams

Question 29

Geothermal: Energy store, Renewable or non-renewable, Uses, Power output, Impact on environment

Answer 29

-thermal -Renewable -Electricity generation, heating -Medium -Very low

Question 30

Tides: Energy store, Renewable or non-renewable, Uses, Power output, Impact on environment

Answer 30

-Kinetic -Renewable -Electricity generation -Potentially very high but hard to harness -Tidal barrages can block sewage which needs to go out to sea

Question 31

Sun: Energy store, Renewable or non-renewable, Uses, Power output, Impact on environment

Answer 31

-Nuclear -Renewable -Electricity generation -Potentially very high, but hard to harness -Very little

Question 32

water waves: Energy store, Renewable or non-renewable, Uses, Power output, Impact on environment

Answer 32

-Kinetic -Renewable -Electricity generation -Low -Very low