structure of the earth

• The core is made up of iron, nickel and sulphur.
• The outer core is liquid
• the inner core is solid
• Gravity


  The force that formed our solar system
• Mass


  A measure of the amount of substance in an object. Objects with a higher mass contain more material.
• Objects with mass


  Are attracted towards each other, we call this force gravitational pull or more commonly weight
• Weight


  A non-contact force. This means objects do not have to be touching to feel a force.
• Formation of our solar system

  Gravity collapsing a massive cloud of dust and gas (a nebula) into the solar system that remains today
• Forces


  • Drawn with arrows from the object's centre of mass, pointing in the direction of the force, with length proportional to the size of the force
• Objects with more mass

  Experience a greater gravitational force
• Bringing two objects nearer each other


  Increases the force of gravity between them
• Investigating the structure of the Earth
• Wave


  Something that transfers energy and information without transferring matter
• Categories of wave


  • Longitudinal waves (vibrations parallel to direction of travel)
  • Transverse waves (vibrations perpendicular to direction of travel)
• P waves (primary waves)


  Longitudinal waves produced by earthquakes, can travel through solids and liquids
• S waves (secondary waves)

  Transverse waves produced by earthquakes, can travel through solids but not liquids
• Earthquake shadow region
• The surface of the Earth is moving
• Convection currents


  Heated fluid decreases in density and rises, cools, increases in density and falls, forming a cyclical motion
• The lithosphere (Earth's crust and top layer of the mantle) is broken down into several plates that can move</b>
• Continental drift


  Theory that the land masses on planet Earth have not always been in their current position and are always moving
• The mantle is mostly magma (molten rock)