3rd Grade

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3rd Grade Ms. Lewko
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Objectives

• You will be able to identify each simple machine.
• You will understand the following terms force,
  effort, and work.
• You will be able to show your knowledge of simple
  machines by drawing, demonstrating, and creating
  a simple machine after we go through this lesson!

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Definitions!!!
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WORK WORK "Work" is only done when something
is moved. To measure the amount of work you do,
multiply the force times the distance the object
moved. Work F x D (work force x distance the
object moved)Force (or weight) is measured in
Newton'sDistance is measured in meters.Unit
measure of work Newton x meter or Newton
meterA Newton meter is called a joule
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eActivityf

• How much work is done when an object is
  lifted?
• MATERIALS
• meter stickNewton spring scaleobjects to
  liftstring pencil and paper j Make a chart to
  record your data.
• kAttach an object to the spring scale.l Slowly
  lift or pull the object. Record how much force
  you used to pull or lift the object (Newtons).m
  Measure the distance you moved the object. Record
  the distance in meters.n Find out how much work
  you did by using the formula,
• workforce x distance the object moved. Record
  your answer on the chart.o Repeat steps 2-5 with
  other objects.

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FORCE You are doing work when you use a force
to cause motion. Machines make work easier, but
they need energy to do work. A person is usually
the source of energy for a simple machine. A
person uses a force to operate a simple machine.
A force is a push or pull. The force applied to
the machine is called work.
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More Vocabulary

• Load- The item to be lifted by the lever
• Fulcrum- What the lever rests on, or rocks on
  when working.
• The point on which the lever moves is called the
  fulcrum.

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Levers

• Levers are probably the most common simple
  machine
• By changing the position of the fulcrum, you can
  gain extra power with less effort.
• A good example of a lever is a see-saw.

Can you think of any other examples
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Three types of levers Animated Levers
                                                  
                                                  
           

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Inclined Plane

• An inclined plane is a slanted surface used to
  raise an object.
• A ramp is an inclined plane.
• When an object is moved up an inclined plane,
  less effort is needed than if you were to lift it
  straight up, but, you must move the object over a
  greater distance.

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Wheel and Axle

• A lever that rotates in a circle around a center
  point or fulcrum. The larger wheel (or outside)
  rotates around the smaller wheel (axle).
• Bicycle wheels, Ferris wheels and gears are all
  examples of a wheel and axle

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A screw is an inclined plane wrapped around a
cylinder, which holds things together or lifts
materials.
The Screw
Examples jar lids, light bulbs, stools, clamps,
key ring
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Wedge

• A wedge is a simple machine used to push 2
  objects apart.
• A wedge is made up of 2 inclined planes. These
  planes meet and form a sharp edge that can split
  things apart.
• This changes the direction of the applied force.

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Pulley

• A single pulley changes the direction of the
  lifting force.
• For example, if you are lifting a heavy object
  with a single pulley anchored to the ceiling, you
  can pull down on the rope to lift the object
  instead of pushing up

Can you name any pulleys that are in your home?
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Project

• Pick your favorite simple machine
• Then using objects from home create your own
  simple machine.
• You have 2 weeks to do this.
• If you need any help, you can always ask me!

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Summary

• Simple Machines

Simple Machines  simple machines - a machine
with a few parts which you can use to do work in
a way that is easier or more effective  effort -
the force needed to operate a simple machine
 force - a push or pull used to lift something,
start it moving, or hold it in place against
another force such as gravity  work - to apply a
force that makes an object move (distance an
object moves times the force
moving it)  energy - the ability to do work or
to cause changes in matter  fulcrum - the
support that acts as a pivot, allowing a lever to
change the direction of a force  joule - (J)
the unit of measurement for energy or work   
For more help...