topic 1

• energy stores (10)

  1) Elastic potential

  2) Gravitational potential

  3) Thermal

  4) Electrostatic

  5) Nuclear

  6) Chemical

  7) Kinetic

  8) Magnetic

  
  

  9) Light

  10) Sound
• Energy transfers

  - Mechanically,

  - Electrically,

  - By heating,

  - Radiation
• Energy transfer - dropping a ball

  Gravitational ---> kinetic
• energy transfer - person throwing a ball

  chemical store (in arm) ---> kinetic store in ball
• Conservation of energy principal

  - States that the total amount of energy in the universe is constant.

  - Energy is neither created nor destroyed, it only changes form.
• What is conduction


  The process where vibrating particles transfer energy to neighbouring particles

  
  

  Happens mainly in solids
• What is convection


  Where energetic particles move away from hotter to cooler regions.

  
  

  Happens only in liquids and gases
• convection currents


  the upward movement of warm air and the downward movement of cool air

  
• How to reduce friction

  Lubricate or oil surfaces
• Insulation (in houses)

  - INSULATING THE LOFT of a house lowers its rate of cooling, meaning less heat is lost to the outside

  - the insulation is often made from fibreglass

  
  

  - CAVITY WALLS: inner and outer walls with air gap in middle. reduces amount of energy transferred by conduction through walls. Foam instead of air prevents convection.

  
  

  - DOUBLE/TRIPLE GLAZED WINDOWS: air gaps between sheets to prevent conduction

  
  

  - DRAUGHT EXCLUDERS around doors and windows; reduce energy transfer through convection
• Investigating the Effectiveness of Materials as Thermal Insulators - Method

  1) boil water in kettle - pour into a sealable container - measure mass and initial temperature

  2) measure temperature using a thermometer

  3) seal the container - leave for 5 minutes

  4) remove lid - measure final temperature

  5) remove water - leave container to cool.

  6) repeat experiment with different materials to see the effectiveness when it comes to insulation
• Is any device 100% efficienct?

  NO - (and wasted energy usually transferred to a thermal store)
• what is non-renewable energy


  energy that has a limited supply and will not renew itself
• what is renewable energy?

  energy with a limitless supply
• Non-renewable energy resources

  coal,

  oil,

  natural gas
• Renewable energy resources


  sun

  wind

  water - waves

  hydro-electricity

  bio-fuel

  tides

  geothermal
• wind power

  
• Wind power pros

  - no fuel costs or emissions

  - generates income for farmers who rent land for turbines or sell electricity

  - short planning and construction time
• wind power cons

  - ruin landscape

  - not enough wind everywhere

  - bird mortality

  - very noisy

  - cant increase power output
• solar energy

  
• solar power pros

  -Produces electricity without air pollution, greenhouse gases, or solid waste

  -No fuel costs

  -Photovoltaic technologies are getting BETTER and CHEAPER
• solar power cons

  - Sun is not always shining;

  - High Price but Coming down in price

  - relatively small scale

  - can't increase power output
• geothermal energy

  
• Geothermal cons

  - aren't many suitable locations

  - cost of building the power plant is high
• Geothermal pros

  - reliable

  - little damage to environment

  - generate electricity or heat buildings directly
• hydro-electric power

  electricity made by water-powered engines

  
• hydro-electric power pros

  - no pollution

  - immediate response

  - no fuel costs

  - minimal running cost

  - good for remote areas
• hydro-electric power cons

  - loss of habitat

  - initial costs are high

  - not look nice if dry
• Tidal barrage


  a dam across the narrow outlet of a tidal basin that uses the ebb and flow of tidal waters to power turbines and dynamos to generate electricity

  
• tidal barrage pros


  - no pollution

  - reliable - go in and out twice a day

  - no fuel costs

  - minimal running costs

  - can generate a significant amount of energy
• tidal barrage cons

  - ruin habitat

  - stop access for boats

  - no guarantee for energy produced

  - does not work if water level is equal on both sides of barrage
• what is bio-fuels

  - made from plants and waste

  - can be burnt to produce electricity

  - or used in cars the same way as fossil fuels

  - supposedly carbon neutral

  - fairly reliable

  - high cost

  - some worry about space used
• Non-renewable fuels reliability

  - fossil fuels and nuclear energy is very reliable

  - enough at the moment to meet demand.

  - however they are slowly running out.

  - fossil fuels are COST EFFECTIVE ways of producing energy.
• Non-renewable fuels problem

  - will run out

  - release CO2 when burnt

  - burning coal releases sulfur dioxide - causes acid rain.

  - mining ruins landscape

  - oil spillages cause serious environmental problems

  - nuclear power is clean but the waste is difficult to dispose of.

  - nuclear power has a risk of causing disaster.
• problems of renewable energy

  - can be expensive

  - arguments over where to put the resources/power plants

  - some energy sources are not as reliable

  - making personal changes can be expensive

  - research takes time and money