1.1

• machine - device that helps us to do work easily and fast
• simple machines

  1. lever
  2. inclined plane
  3. screw
  4. wheel and axle
  5. pulley
  6. wedge
• first class lever

  • fulcrum is in the middle
  • it is between the load and the effort
  • ex. scissors, see - saw
• second class lever

  • load is in the middle
  • it is in between the fulcrum and the effort
  • ex. wheelbarrow, pushups
• third class lever

  • effort is in the middle
  • it is between the load and the fulcrum
  • ex. chopsticks, hockey stick
• inclined plane - a flat surface at an angle

  • makes it easier to lift heavier objects
  • exerts less force over a larger distance
  • ex. ramp
• wedge - driven between two objects or parts of an object to separate them

  • A force in one direction is converted to a force in a perpendicular direction
  • The wedge moves greater distance into an object than the split it causes
  • ex. knife, axe
• screw -

  • consists of a cylinder with a groove cut in a spiral on the outside
  • Helps to increase the force you use
  • Can be used to convert rotational motion to linear motion
  • Ex. screw
• Archimedes screw - a screw inside of a large tube, placed in water

  • when turned, it raises water to the top of the tube
  • used to move large volumes of water
• pulley (block and tackle) -  made up of a wire, rope, or cable moving on a grooved wheel

  • can have one or more wheels
  • can be fixed in place or moveable
  • can be linked together in systems
• wheel and axle -

  • Simple machine made up of two wheels of different diameters that turn together
  • A longer motion on the wheel produces a shorter but more powerful motion at the axle 
  • Uses a wheel and axle to increase the size of the force
  • Have to turn a greater distance to apply the force
  • Can also be used to increase speed
• effects of simple machines

  1. change the direction of force (using a pulley to move a flag)
  2. multiply force (screw driver)
  3. increase or decrease speed
  4. transferring force
• potential energy - energy stored in an object due to its position or shape. (energy that could be) ex. biker on top of hill
• kinetic energy - energy of an object due to its motion