P1 - Energy Flashcards
Energy stores Examples
- Thermal
- Kinetic
- Gravitational potential
- Elastic potential
- Chemical energy
- Magnetic
- Electrostatic
- Nuclear
Kinetic energy equation
E = 1/2mv^2
kinetic energy = 1/2 x mass x (speed)^2
Gravitational potential equation
E = mgh G.P.E = mass x gravitational field strength x height
elastic potential equation
E = 1/2ke^2 E.P.E = 1/2 x Spring constant x extension
Specific heat energy equation
change in E = mc(change in)temperature
change in E = mass x S.H.C x change in temperature
power equation
P = w/t power = work done/time
conservation of energy principle
energy can be transferred usefully, stored or dissipated, but can never be created or destroyed.
ways to reduce unwanted energy transfers
lubrication
thermal insulation
Lubrication
Lubricants can be used to reduce the friction between the objects’ surfaces when they move.
conduction
the particles vibrate more and collide with each other. During these collisions, energy is transferred between the particles’ kinetic energy stores
convection
Materials with a higher thermal conductivity transfer energy between their particles at a faster rate. The particles are free to move the space between individual particles increases . This causes the density of the region being heated to decrease. Energetic particles move away from hotter to cooler regions.
cavity walls
made up of inner and outer wall and have an air gap in the middle. The air gap reduces the amount of energy transferred by conduction in the walls.
loft insulation
can reduce convection currents being created in lofts.
double-glazed windows
they have an air gap between two sheets of glass to prevent energy transfer by conduction through windows
drought excluders
around doors and windows to reduce energy transfers by convection
efficiency equation
efficiency = useful output / total output
non renewable resources examples
coil
oil
natural gas
renewable resources examples
the sun wind water waves hydro-electricity bio-fuel tides geothermal
non-renewable resources
run out one day
damage the environment
provide most of our energy
renewable resources
never run out
most of them do damage but not as bad as non-renewable
don’t provide much energy
some are unreliable as they depend on the weather.
Transport energy resources
N
- petrol and diesel use fuel created from oil
- coal is used in some old-fashioned steam trains
R
- Vehicles that run on pure bio-fuels
Heating energy resources
N - Natural gas is used to heat up water - coal for fire places - Electric heaters which uses energy generated from NRR R - A geothermal heat pump - Solar water heaters work by using the sun to heat up water - Burning bio-fuel
wind power
- no pollution
- spoil the view
- very noisy
- initial costs are high but no fuel or minimal running costs
- no permanent damage to the landscape
Solar cells
- remote places
- no pollution
- only in daytime
- initial costs are high
- energy is free and running costs are almost nil.
- generate electricity on a relatively small scale
Geothermal power
- where hot rocks are quite near the surface. Slow decay of various radioactive elements deep inside the earth
- free energy
- reliable
- little damage to the environment
- generate electricity or heat buildings directly
hydro-electric power
- requires the flooding of a valley by building a big dam
- no pollution
- big impact on the environment - flooding of valley and possible loss of habitat
- unsightly when dried up
- provide an immediate response
wave power
- lots of small turbines around the coast
- no pollution
- disturbs the seabed and the habitats of marine animals
- hazard to boats
- spoil the view
- large scale
Tidal Barrages
- big dams with turbines build into them
- gravitational pull of the sun and moon
- no pollution
- preventing free access by boats
- altering habitat
- spoils the view
- happen twice a day with no fail
- lower tides will provide less energy than bigger tides
Bio-fuels
- renewable energy source
- created from plant products or animal waste
- solid, liquid or gas and can be burnt to make electricty
- fairly reliable as crops take a relatively short time to grow
- cannot respond to immediate energy demands
- stored for when they are needed
- cost is very high
- some regions have large forests cleared and use them for bio-fuels. This means a lot of animals are losing their habitats
- Burns vegetation and it increases CO2 and methane emmisons
ways in which non-renewables are reliable
- enough fossil and nuclear fuels to meet current demands
- extracted from the earth at a fast enough rate that power plants always have fuel in stock
- respond quickly to changes in demand
- running and fuel extraction costs are fairly low
Non-renewables creating environmental problems
- coal, oil and gas release CO2
- coal and oil releases sulfur dioxide
- coal mining can spoil the view
- oil spillages
- nuclear waste
- nuclear power
Why we still depend on fossil fuels
- electricity
- oil is used to fuel cars
- gas is used to heat homes and cook food
Why people want more renewable energy resources
- very damaging to the environment
- non-renewables will run out
- pressure from other countries
- car companies have been affected by this change in attitude
Renewables are limited
- building power plants costs money
- arguments of where to put them
- some energy resources are unreliable
- personal changes can be quite expensive
