PSCI4 12

• Fossil fuels


  Fuels made from decomposing plants and animals, found in Earth's crust, containing carbon and hydrogen that can be burned for energy
• Fossil fuels


  • Coal
  • Oil
  • Natural gas
• Coal


  • Usually found in sedimentary rock deposits where rock and dead plant and animal matter are piled up in layers
  • More than 50 percent of a piece of coal's weight must be from fossilized plants
• Crude oil/petroleum/Oil


  • Originally found as a solid material between layers of sedimentary rock, like shale
  • Heated to produce the thick oil that can be used to make gasoline
• Natural gas


  • Usually found in pockets above oil deposits
  • Can also be found in sedimentary rock layers that don't contain oil
  • Primarily made up of methane
• Advantages of fossil fuels

  • Available abundantly in our environment
  • Available at a cheaper rate
  • Easy to store and transport
  • Boost up the economy of a nation
  • Power stations can be built almost anywhere
• Disadvantages of fossil fuels

  • Non-renewable resources
  • Responsible to pollute the environment
  • Unsustainable
  • Hazardous in nature
  • Residue remaining after combustion is also harmful to the environment
• Geothermal energy


  Heat produced deep in the Earth's core, a clean, renewable resource that can be harnessed for use as heat and electricity
• Sources of geothermal energy

  • Heated underground rock formations
  • Magma in the mantle and lower crust
  • Hot water released through geysers, hot springs, steam vents, underwater hydrothermal vents, and mud pots
• Advantages of geothermal energy

  • More environmentally friendly than conventional fuel sources
  • Small land footprint
  • Renewable energy source
• Disadvantages of geothermal energy

  • Location specific
  • Expensive initial cost
  • Can release small amounts of greenhouse gases
• Hydroelectric energy


  Energy that harnesses the power of water in motion to generate electricity
• Hydroelectric power plants


  • Have a reservoir of water
  • Have a gate or valve to control water flow
  • Have an outlet where the water ends up after flowing downward
• Potential energy


  Energy a body has by virtue of its position or state
• Kinetic energy


  Energy a body possesses by virtue of being in motion
• Advantages of hydroelectric energy

  • Cheap to run
  • No polluting of gases produced
  • Reliable
  • Adjustable
  • Create Lakes
  • Land Development
• Disadvantages of hydroelectric energy

  • Damage to the estuary habitats
  • Flood Risk
  • Limited locations to build dams
  • Water cycles of abundance and drought
  • Higher initial cost
• Johannes Kepler


  German astronomer, mathematician, astrologer, natural philosopher and writer on music, best known for his laws of planetary motion
• Kepler's First Law (Law of Ellipses)


  Planets move in ellipses with the Sun at one focus
• Kepler's first law explains that planets are orbiting the sun in a path described as an ellipse
• Aphelion


  Greatest distance between a planet or other body and the Sun
• Perihelion


  Closest distance from the Sun
• Objects move slowest in their orbits when they are at aphelion and fastest when at perihelion
• Kepler's Three Laws


  1. The Law of Ellipses

  2. The Law of Equal Areas

  3. The Law of Harmonies
• The Law of Ellipses

  The path of the planets about the sun is elliptical in shape, with the center of the sun being located at one focus
• The Law of Equal Areas


  An imaginary line drawn from the center of the sun to the center of the planet will sweep out equal areas in equal intervals of time
• The Law of Harmonies


  The ratio of the squares of the periods of any two planets is equal to the ratio of the cubes of their average distances from the sun