Please enable JavaScript.
Coggle requires JavaScript to display documents.
Energy stores an transfers II - Coggle Diagram
Energy stores an transfers II
Reducing unwanted energy transfers
Lubrication
Whenever something moves, usually there is a frictional force acting against it, causing energy to be dissipated
Lubricants can reduce the friction between object's surfaces
Insulation
Thicker walls - low thermal conductivity, heat energy is lost slower
Cavity walls - Walls have an air gap which is filled with foam, so reduces convection
Loft insulation - reduces convection currents due to warm air rising
Double glazed windows - An air gap between two sheets of glass prevent convection
Draught excluders - go around windows and doors to reduce thermal energy being lost
Thermal conductivity
The higher the thermal conductivity of a material, the more easily heat is allowed to travle trhouhg the material, and the hgiher the rate of energy transfer by conduction across it
In a building
Rate of cooling is low if the walls are thick and the thermal conductivity is low
If walls are thin, heat would be lost very easily, meaning a high thermal conductivity
Energy resources
Non-renewable
fossil fuels and nuclear fuels
Fossil fuels: coal, oil, Natural gas
Will all run out
Damage the environment
Reliable
Large energy ouput per kilogram
Renewable
Solar, wind, hydroelectric, bio-fuel, geothermal
Will never run out
Damage is less that non-renewable
Don't provide as much energy
Unreliable as they depend on weather
Being replenished as it is used
Uses of energy
Transport
Non-renewable
Petrol and diesel cars
Coal to create steam for trains
Renewable
Vehicles that run on biofules
Heating
Non-renewable
Natural gas, used to heat water
Coal, burnt in fireplaces
Electric heaters use electricity generated from non-renewable sources
Renewable
geothermal energy
solar water heaters
Burning bio-fuel or using renewably generated electricity
Specific heat Capacity Practical
Apparatus - Water, thermometer, electric heater, power supply, insulation, beaker, electronic balance
Method
1) Measure the mass of the water
2) Record the potential difference and current of the power supply
3) Take the temperature every 30 seconds. At the end, record the change in temperature
4) Plot a graph of temperature against time
5) To calculate SHC, use this equation. c = (VIt) / (m X change in temp)
Voltage X current X time = energy
Thermal Insulation practical
Apparatus - beakers, thermometers, kettle and water, cardboard, stopwatch, insulating materials
Method
Investigating thickness
1) Wrap three beakers with different layers of the same material
2) Put the same amount of water into each beaker
3) Place a cardboard lid on top with a hole for the thermometer
4) Record the temperature of the water at set intervals
5) Put your results in a table, then plot a graph, temperature against results and compare
Investigating material
1) Place some insulating material around a beaker
2) Pour water into the beaker
3) Place a piece of cardboard with a whole for the thermometer
4) Record the temperature at set intervals
5) Retry with different materials
6) Plots your results in a graph, temperature against time and compare results
Energy resources
Bio-fuels (R)
Taken from recently living or recently living organisms including methane from animal waste
Used for fuels methanol in transport and as fuel in power stations
Carbon neutral, CO2 released when its burnt is the same that the organism took in when living
Wind (R)
Wind turbines transfer kinetic energy of the wind to electrical energy by turning a generator
Doesn't work when there isn't much wind
Very noisy
No pollution
Hydroelectricity (R)
Reservoir water is used to generate electricity when it passes through a turbine
Valleys may need to be flooded
Generally reliable, not in a drought
No pollution
Geothermal (R)
Released from radioactive decay within the Earth heats surrounding rocks
Water is pumped down to be heated by the rocks
Resulting hot water or steam is used to heat homes or turn generators
Reliable due to consistent heat supply
Tidal power (R)
Kinetic enegry of tidal streams or from sea water flowing through barrages is used by turbines to generate electricity
Tidal power is available at predictable times, but not all the time
It can affect wildlife in certain places
Solar Power (R)
Solar panels use radiation from the Sun to heat water for use in homes or generate electricity
Can be used to supply enegry to people in remote areas
Doesnt work when it isnt sunny
Water waves (R)
Water waves turn a generator to generate electricity
Unreliable due to small or no wave motion on calm days
Fossil fuels (NR)
Coal, oil and gas are burned in power stations to heat water, which becomes steam and turns turbines to generate electricity
Fuels such as petrol, kerosene, diesel and oil are used in transport and heating homes
Reliable, but produces carbon dioxide which leads to global warming
Nuclear (NR)
Uranium or plutonium release energy from the fission of their nuclei
The energy released is used in power stations to generate electricty
Reliable, produces around 10,000 times more energy per kilogram compared with fossil fuels
Also produces large amounts of dangerous radioactive waste
Zero CO2 emissions
Conservation of energy
Energy can be tansferred
Energy can be wasted of dissipated
Energy cannot be created or destroyed
The total energy in a closed system is the same after as it was before the transfer
A closed system is an isolated system where no energy flows in and out of the system