Section 4- Energy Resources and Energy Transfer

Section 4- Energy Resources and Energy Transfer

1. Sankey Diagrams

   • Energy Input = Energy Output

2. Heat Transfer

   • Heat always goes from HOT to COLD
   • Conductors + Insulators
   • Conduction
     • Heat vibrations= amplitude
     • Metals have free electrons that can travel down the particle line and collide with others further along which speeds up the process- hence metals being good conductors.
   • Convection
     • Low energy, more dense, sinking, slower, further from heat source
     • High energy, less dense, rising, faster, closer to source
   • Radiation
     • Wave- Infra-red radiation
       • All objects above absolute zero emit and absorb infrared radiation.
         • An object hotter than its surroundings emits more radiation than it absorbs (as it cools down).
         • An object cooler than its surroundings absorbs more radiation than it emits (as it warms up).
         • Good reflector, poor absorber and emitter
         • best absorber and emitter

3. Insulation

   • Preventing heat transfer and stopping heat escaping.
   • Draught proof strips under door
   • Prevents convection + conduction
   • Vacuum Flask
     • Silver inside- prevents radiation
     • Screw cap- prevents convection and evaporation
     • Vacuum- no air inside prevents conduction and convection
     • Poorly conducting material- prevents conduction

4. Work and Power

   • Work done (J) = Energy transferred (J)
   • Work done (J) = Force (N) x Distance (m)
   • Power (W) = Work done (J) / Time (s)
   • Power (W) = Current (A) x Voltage (V)

5. Gravitational Potential Energy and Kinetic Energy

   • Work done (J) = Energy transferred (J)
   • GPE = Mass (Kg) x Gravitational field strength (N/Kg) x Height (m)
     • GPE = mgh
     • Therefore, m = GPE / (g x h)
   • Kinetic energy (J) = 1/2 x Mass (Kg) x Velocity2 (m/s)
   • Law of conservation of energy = Ek max = Ep max
     • Ek= Kinetic energy Ep= GPE

6. Generating Electricity

   • Fossil fuels
     • Non-renewable + pollutes environment
     • Quick + easy method
     • Chemical
       • Heat
         • Kinetic
           • Electrical
     • Things that affect national grid electricity demand= time of day+year
   • Nuclear Reactor
     • Atoms of uranium or plutonium do nuclear fission. Releases lots of heat energy. Heat turns water into steam which turns a turbine attached to a generator, generating electricity.
     • Nuclear
       • Heat
         • Kinetic
           • Electrical
     • A neutron is fired at a uranium nucleus to make it split. This creates heat energy. It's products are more neutrons and daughter nuclei.
     • Renewable and efficient but creates nuclear waste which is buried and dangerous. Radioactivity contamination is a risk and they only last a certain number of years then have to be taken down.

7. Renewable Energy

   • Wind Turbines
     • Kinetic
       • Kinetic
         • Electric
   • Hydroelectric Power
     • GPE
       • Kinetic
         • Kinetic
           • Electrical
   • Tidal + Wave
     • Kinetic
       • Kinetic
         • Electrical
   • Solar Cells
     • Light
       • Electrical
   • Solar Panels
   • Geothermal
   • Carbon Capture
   • Carbon neutral

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