Simple Machines

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Chapter 9.2

• Simple Machines

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The 6 Simple Machines

• All machines are made up of some of the 6 simple
  machines. They are
• Wheel and axle
• Pulley
• Lever
• Wedge
• Screw
• Inclined Plane

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The 6 Simple Machines
Lever
Inclined Plane
Pulley
Wheel and Axle
Wedge
Screw
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SIMPLE MACHINES

• LEVER
• A lever is a simple machine.  It is a board or
  bar that rests on a turning point.  This turning
  point is called the fulcrum.  An object that a
  lever moves is called the load.  The closer the
  object is to the fulcrum, the easier it is to
  move.  

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Levers

• Let's examine the lever
• Three parts
• Fulcrum or pivot point
• Loaded lever arm
• Effort (push or pull) lever arm

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The Lever - can change the direction of the
force - can multiply the force of the
effort Three types of levers based on the
position of the fulcrum (or pivot point).
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EXAMPLES OF LEVERS

• Bottle openers
• Crow bars
•  

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SIMPLE MACHINES

• WHEEL AND AXLE
• The wheel and axle is another simple machine. 
  The axle is a rod that goes through the wheel. 
  This lets the wheel turn.  It is easy to move
  things from place to place with wheels and
  axles. 

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The Wheel and Axle

• Two or more wheels are connected by an axle.
• The wheel turns with or around the axle.
• This car wheel has a big axle that it rotates
  around when the car moves.

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The wheel and axle - multiplies the effort
distance or force
The captain uses a large wheel to apply a greater
force to a small axle which controls the
steering of the ship.
This shows that a small axle (handle) attached to
the grind stone, increase the distance that the
stone wheel moves.
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EXAMPLES OF WHEEL AND AXLE

• Cars
• Roller Skates
• Wagons
• Door Knobs
• Gears in Watches, Clocks, and Bicycles

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SIMPLE MACHINES

• INCLINED PLANE
• A simple machine that is a flat surface that is
  higher on one end.  You can use this machine to
  move an object to a lower or higher place. 
  Inclined planes make the work of moving things
  easier.  You would need less energy and force to
  move objects with an inclined plane. 

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The Inclined Plane

• It is a slanted surface or ramp.
• It makes moving objects easier.
• Roads are also inclined planes. Instead of going
  straight up, like this roads go up at small
  angles, like the picture.

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SIMPLE MACHINES

• WEDGE
• A wedge is a simple machine used to push two
  objects apart.  A wedge is made up of two
  inclined planes.  These planes meet and form a
  sharp edge.  This edge can split things
  apart.  

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The Wedge

• A wedge is used to split, tighten, or secure a
  hold.
• A wedge is usually a triangle shape with a sharp
  point.
• If you apply force at one end, the wedge will go
  between something, in this case an ax splits a
  piece of wood.

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Where can we find wedges?

• Wedges that split
• Your teeth!
• Every time you bite into something, you are using
  a wedge.
• Wedges that cut
• A saw!
• A knife!

• Wedges that tighten
• A doorstop to keep the door open.
• Wedges that hold things together
• A nail holds wood to a wall or other wood.

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SIMPLE MACHINES

• SCREW
•   A screw is a simple machine that is made from
  another simple machine.  It is actually an
  inclined plane that winds around itself.  A screw
  has ridges and is not smooth like a nail.  Some
  screws are used to lower and raise things.  They
  are also used to hold objects together. 

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EXAMPLES OF SCREWS

• Jar Lids
• Light Bulbs
• Stools
• Clamps
• Spiral stairs
• Jacks (to lift car so you can change the tire)

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Archimedes Screw

• used in ancient times to bring water up from the
  river.

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SIMPLE MACHINES

• PULLEY
• This simple machine is made up of a wheel and a
  rope.  The rope fits on the groove of the wheel. 
  One part of the rope is attached to the load. 
  When you pull on one side of the pulley, the
  wheel turns and the load will move.  Pulleys let
  you move loads up, down, or sideways.  Pulleys
  are good for moving objects to hard to reach
  places.  It also makes the work of moving heavy
  loads a lot easier.