Topic 1 - Energy

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Created by
Holly Haggarty

Cards (29)

  • System

    An object or group of objects
  • When a system changes

    The way energy is stored also changes
  • Ball rolling and hitting a wall
    • Moving ball
    • Kinetic energy transfers as sound
  • Vehicle slowing down

    • Vehicle moving
    • Kinetic transfers to thermal due to friction
  • Kinetic Energy

    πΈπΈπ‘˜οΏ½οΏ½ = 1
    2 π‘šπ‘šοΏ½οΏ½π‘£2
  • Elastic Potential Energy

    𝐸𝐸𝑒�� = 1
    2 π‘˜π‘˜οΏ½οΏ½π‘’2
  • Gravitational Potential Energy

    𝐸𝐸𝑝𝑝 = π‘šπ‘šπ‘šπ‘šβ„Ž
  • Specific Heat Capacity

    • The energy required to raise the temperature of 1kg of a substance by 1Β°C or 1K
    • 𝐸𝐸 = π‘šπ‘šοΏ½οΏ½π‘šβˆ†π‘‡π‘‡
  • Power

    𝑃𝑃 = 𝐸𝐸
    𝑑𝑑 = π‘Šπ‘Š
    𝑑𝑑
  • An energy transfer of 1 joule per second is equal to a power of 1 watt
  • If given two motors A and B, the motor that can do the same work faster
    Is more powerful
  • Energy can be transferred usefully, stored or dissipated but cannot be created or destroyed
  • In all system changes energy is dissipated, so that it is stored in less useful ways. This energy is often described as being 'wasted'
  • Reducing energy waste

    • Lubrication
    • Thermal Insulation
  • Thermal Conductivity

    The higher the thermal conductivity of a material, heat is allowed to travel through the material more easily, so the higher the rate of energy transfer by conduction across the material
  • Thermal Conductivity in a building
    Rate of cooling is low if walls are thick and thermal conductivity of the walls are low
  • If the walls are thin metal sheets, heat would be lost very quickly
  • Efficiency

    • The ratio of the useful work done by a machine, engine, device, etc, to the energy supplied to it, often expressed as a percentage
    • 𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒��𝑒𝑒𝑒𝑒𝑒𝑒𝑒 = 𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 π‘’π‘’π‘’π‘’π‘’π‘’π‘’π‘’π‘šπ‘šπ‘’π‘’ π‘œπ‘œπ‘’π‘’π‘‘π‘‘π‘π‘π‘’π‘’π‘‘π‘‘
    π‘‘π‘‘π‘œπ‘œπ‘‘π‘‘π‘‘π‘‘π‘’π‘’ π‘’οΏ½οΏ½π‘’π‘’π‘’π‘’οΏ½οΏ½π‘’π‘šπ‘šπ‘’π‘’ 𝑒𝑒𝑒𝑒𝑝𝑝𝑒𝑒𝑑𝑑
  • Ways to increase efficiency
    • Reducing waste output
    • Recycling waste output
  • Main Energy Sources

    • Non-renewable: Fossil Fuels, Nuclear Fuel
    • Renewable: Biofuel, Wind, Hydro-electricity, Geothermal, Tidal, Solar, Water waves
  • Renewable energy

    Energy which can be replenished as it is used
  • Non-renewable energy

    Used more for large-scale energy supplies due to the large energy output per kilogram of fuel
  • Renewable energy has become more important due to the finite lifetime of fossil fuels, and so their development has become more important
  • Renewable energy is not always the most reliable as: solar doesn't work in bad weather or night, wind is only intermittent
  • Main Energy Uses

    • Transport
    • Electricity generation
    • Heating
  • Environmental Impact of Energy
    • Extraction: Fossil fuels destroy landscapes, wind turbines can be eyesores
    • Use: Fossil fuels release harmful emissions, solar/wind create electricity with no emissions
  • During industrial revolution, fossil fuels became an important source of energy as it was easy to mine, and provided a lot of energy
  • Only recently has renewable energy become more suitable – technology has had to develop a lot since industrial revolution to be able to harness such energy sources efficiently
  • It is easier to use energy resources due to increasing pressure to cope with the public's increasing power demands but harder to solve environmental issues due to political, social, ethical and economic considerations