energy

Question 1

energy stores

Answer 1

thermal energy
gravitational energy
elastic energy
kinetic energy
nuclear energy
electrostatic energy
magnetic energy
chemical energy

Question 2

two types of work done

Answer 2

mechanical
electrical

Question 3

open system is

Answer 3

a system that can gain or lose energy to the outside world

Question 4

kinetic energy definition

Answer 4

energy that it possesses due to its motion

Question 5

key concepts of kinetic energy and gravitational potential energy

Answer 5

as an object rises ke is converted to gpe
as an object falls gpe is converted to ke
ke lost = gpe gained
and ke gained = gpe lost

Question 6

specific heat capacity definition

Answer 6

the amount of energy needed to raise the temperature of 1kg of a substance by 1 degree Celsius

Question 7

what is efficiency

Answer 7

the proportion of the energy supplied that is actually transferred into useful energy output

Question 8

what is the law of conservation of energy

Answer 8

energy cannot be created or destroyed it can only be transferred usefully to other objects or forms or be dissipated to the surroundings as waste energy

Question 9

what are the main energy resources

Answer 9

fossil fuels such as coal oil gas
these are non renewable
renewable sources such as bio fuel wind hydro electricity geothermal tidal solar and water waves are also used

Question 10

renewable energy source meaning

Answer 10

an energy resource that can be or is being replenished as it is used

Question 11

what is a fossil fuel

Answer 11

a fossil fuel is a hydro carbon containing material formed naturally in the earths crust from the remains of dead plants or animals

Question 12

name the fossil fuels

Answer 12

coal crude oil natural gas

Question 13

what can fossil fuels do when burned

Answer 13

provide heat for direct use such as cooking
to power engines e.g internal combustion in cars
to generate electricity

Question 14

pros and cons of fossil fuels

Answer 14

pros
relatively cheap
can be used in any condition doesn’t require specific weather
most of our current infrastructure is designed on running on fossil fuels

cons
they are a limited resource so they will run out
they produce coz when burned which is a green house gas and contributes to global warming
they sometimes produce toxic gases when burned

Question 15

how is nuclear energy obtained and what can it do

Answer 15

by nuclear reactions such as nuclear fission reactions
they generate electricity which can be transmitted to homes and factories

Question 16

pros and cons of nuclear energy

Answer 16

pros
nuclear energy does not produce any pollutants
can be used in any conditions
although it is a finite resource is it very unlikely to run out for a very long time
cons
it is still a finite resource
nuclear power stations produce radioactive waste which remains harmful for thousands of years and must be stored carefully
it is expensive

Question 17

pros and cons of wind and solar

Answer 17

pros
low running cost
don’t produce any pollutants
they don’t damage the environment

cons
high upfront cost
making them produces pollutants
now way ti increase supply in times of peak demand
they are an eye sore

Question 18

how do wind turbines convert energy

Answer 18

they convert kinetic energy when the blades spin into electrical energy

Question 19

what is geothermal energy

Answer 19

thermal energy generated and stored in the earths crust from radioactive decay

Question 20

pros and cons of geothermal energy

Answer 20

pros
running it doesn’t produce any pollutants
installing only damages environment slightly
renewable

cons
only use this source in certain areas such as volcanic areas
power plans can be expensive to build

Question 21

what is biofuels

Answer 21

fuels that made from recently living organisms

Question 22

pros and cons of biofuels

Answer 22

pros
a renewable resource
cheap to make
easy to transport
mix them with fossil fuels

cons
need somewhere to grow the plants which could involve cutting down forests
harvesting processing and transport of biofuels all require energy which may release co2

Question 23

pros and cons of hyrdro electric damns and tidal barrages

Answer 23

pros
large amounts of energy with no pollution
reliable sources of electricity
running costs are fairly low
work both large and small scales
cons
often have a big impact on the surrounding environment
initial set up is expensive
often flood huge areas
sometimes stop boats and fishes from travelling

Question 24

specific heat capacity required practical

Answer 24

place a beaker on a balance and press zero button
now add oil to the beaker and record the mass of the oil
place a thermometer and an immersion heater into the oil
read the starting temperature of oil
wrap beaker in insulating foam to reduce thermal energy transfer to surroundings
connect power pack and joulemeter
time 30 mins
read how many joules passed into heater and read final temp of oil
now use specific heat capacity equation