energy Flashcards
energy stores
thermal energy
gravitational energy
elastic energy
kinetic energy
nuclear energy
electrostatic energy
magnetic energy
chemical energy
two types of work done
mechanical
electrical
open system is
a system that can gain or lose energy to the outside world
kinetic energy definition
energy that it possesses due to its motion
key concepts of kinetic energy and gravitational potential energy
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
specific heat capacity definition
the amount of energy needed to raise the temperature of 1kg of a substance by 1 degree Celsius
what is efficiency
the proportion of the energy supplied that is actually transferred into useful energy output
what is the law of conservation of energy
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
what are the main energy resources
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
renewable energy source meaning
an energy resource that can be or is being replenished as it is used
what is a fossil fuel
a fossil fuel is a hydro carbon containing material formed naturally in the earths crust from the remains of dead plants or animals
name the fossil fuels
coal crude oil natural gas
what can fossil fuels do when burned
provide heat for direct use such as cooking
to power engines e.g internal combustion in cars
to generate electricity
pros and cons of fossil fuels
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
how is nuclear energy obtained and what can it do
by nuclear reactions such as nuclear fission reactions
they generate electricity which can be transmitted to homes and factories
pros and cons of nuclear energy
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
pros and cons of wind and solar
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
how do wind turbines convert energy
they convert kinetic energy when the blades spin into electrical energy
what is geothermal energy
thermal energy generated and stored in the earths crust from radioactive decay
pros and cons of geothermal energy
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
what is biofuels
fuels that made from recently living organisms
pros and cons of biofuels
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
pros and cons of hyrdro electric damns and tidal barrages
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
specific heat capacity required practical
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
