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  • Simple Machines – a mechanical device that can be used to change the direction of a force or multiply force (change magnitude)
  • Lever – rigid bar that turns around a pivot called the fulcrum.
    – used to help move or lift a heauy or fixed load on one end when force is applied on the other end.
  • Effort – the force that you exert at one end of the object to lift the load on the other end Effort arm – the distance from the part of the lever where you exert force to the fulcrum.
  • Load / Resistance – the weight you need to lift. Resistance arm – the distance from the part of the lever where the load is located to the fulcrum.
  • First class lever – the fulcrum is between the load and the effort Ex. pliers, crowbar, scissors, hammer with a claw, shovel
  • Second class lever – shows the load/resistance is between the effort and the fulcrum Ex: Wheelbarrow – wheel → fulcrum, weight in the wheelbarrow → load/resistance, force applied on the handle → effort Nutcrackers and bottle openers
  • Third class lever – has the effort in between the fulcrum and the load. – Cannot lift heavy objects Ex. tweezers, sugar tong, fishing rod
  • Inclined Plane – flat surface with one end higher than the other. – reduces the force or effort heeded to move an object up to a higher place or bring it down to a lower place; however, the distance is increased.
  • Screw – an inclined plane wrapped around a cylinder or pole that is used to hold things together like pieces of woods to support parts of furniture or pieces of metals that make up a machine – has two important parts: the thread and the pole or cylinder; distance between threads is called pitch. Ex. jackscrew, bottle caps
  • Wedge – sometimes referred to as a double inclined plane. – has a sharp edge and is usually used for cutting or splitting objects; application of a small force can already overcome a large resistance. Ex. Knife – can be used in cutting meat Axe
  • Fixed Pulley – does not travel with the load. A load is attached to one end of the cord that passes through the pulley while the effort or force is applied on the other end of the cord; the load moves up when a downward force is applied on the other end of the cord.
  • Movable Pulley – moves along the rope together with the load; is used to multiply the applied force. – is attached to the object you are moving; however, a movable pulley does not change the direction of the applied force.
  • Block and Tackle Pulley – combination of a fixed pulley and movable pulleys.
  • Fact : The diameter of the Earth is nearly 8 000 miles, meaning you’d have to dig 15 feet per day for 4 000 years to reach the center of the Earth.
  • Crust (around 5-25m thick)– Earth's solid, thinnest, outermost layer – relatively cold, is rocky and brittle; can fracture during earthquakes – consists of plates that are either continental or oceanic.
  • Continental Plate (30-50 km thick) – contains the different landforms and continents. Oceanic Plate (about 8-10 km thick) – heavier, denser, and darker than the continental crust – consists the landforms below the oceans and seas.
  • Endogenic Forces – are those that come from within the Earth. – force produced by convection current in the mantle Exogenic forces – are those that develop outside the surface of Earth. – force of the wind
  • Mantle (1800m thick) – made up of magma and is divided into the upper mantle, asthenosphere, and lower mantle – is so massive, it makes up a total of 84% of Earth’s volume
  • Magma – part of the asthenosphere which is extremely hot, dense, rock; flows like asphalt
  • Upper Mantle (1600°F) – made of solid bedrock that contains most of Earth's mass. – lower lithosphere and the asthenosphere are both part of the upper mantle.
  • Lithosphere – made up of granite and basalt by the crust and upper mantle which is rigid, hard; makes up the tectonic land plates about 100 km thick. Asthenosphere – soft layer made up of granite and basalt, beneath the lithosphere which’s temperature and pressure are so high that rocks melt.
  • Fact : Lithosphere makes up the tectonic plates, and the asthenosphere is the material they float on.
  • Core – innermost layer of the Earth which consists of the outer core and the inner core.
  • Outer core (1400m thick)– is located about 1800 miles below the Earth’s surface; made up of molten iron and nickel with about 10 percent sulfur; has temperatures between 4000 and 9000 degrees Inner core – is made up of solid iron and nickel; under extreme pressure that is why it remains solid
  • Alfred Wegener – German geologist and meteorologist who first proposed the continental drift theory in 1912.
  • Pangaea – one giant supercontinent , meaning all lands, which was surrounded by a single ocean called Panthalassa. Pangaea, over time had separated and drifted apart
  • Theory of Plate Tectonics – tells that the surface of Earth is divided into several pieces of plates that "float" along the asthenosphere. – explains how the different geological phenomena like earthquake, volcanism, continental drift, and mountain formation occur.
  • Tectonic Plates – plates move along their boundaries in different directions and at different speeds.
  • Earth’s interior is very hot; release of heat from the core produces convection current in the mantle.
  • Convection Current – causes the oceanic and continental plates to move.
  • Convergent Plate Boundary – formed when plates meet from opposite directions causing one plate to be subducted or moved beneath the other.
  • Two oceanic plates collide with one another, one may be pushed under the other.
  • when an oceanic plate collides with a continental plate, the oceanic plate is subducted beneath the continental plate; forms a huge mountain or a deep oceanic trench.
  • Divergent Plate Boundary – formed when two tectonic plates move away from each other. Rift – the sunken blocks form a valley Seafloor Spreading – When two ocean plates move apart, magma rises from the mantle to fill the gap. When magma cools, a new seafloor is formed.
  • Transform / Sliding Boundary Plate – zone between two plates sliding horizontally past one another – causes friction and a strong jerky motion of the plates as they move apart, which produces an earthquake.