2. WHAT ARE SIMPLE MACHINES?
• A simple machine is a device that makes work
easier. They often change the direction or
magnitude of a force and offer mechanical
advantage.
• Simple machines are seen as the building
blocks of more complex machines.
• Simple machines allow an applied force to work
against a load force.
3. HOW DID WE FIGURE ALL OF THIS OUT?
• The group of devices were defined by
renaissance scientists and are widely used to
this day!
• Archimedes first theorized the simple machine,
but mainly studied the lever, pulley and screw.
These three are known as the “Archimedean”
simple machines. What a guy!
• Also, our old favorite Galileo Galilei was the first
to discover that the machines did not create
energy they just transformed it. He wrote about
this in his publication: “Le Meccaniche” (on
mechanics)
4. HOW MANY SIMPLE MACHINES ARE THERE?
There are a total of 6 simple machines:
1.Lever
2.Inclined Plane
3.Wheel and Axle
4.Screw
5.Wedge
6.Pulley
5. THE LEVER
• The lever is made by constructing some type of
beam (long straight piece of material) and
attach it to a fulcrum.
• This design allows the input force to be
magnified for a greater output force.
6. THE LEVER (CONTINUED)
• There are 3 classes of levers and they all
depend on where the fulcrum is:
1. Class one- fulcrum is in the middle (see-saw
or scissors)
2. Class two- Fulcrum is on opposite side of
where the force is being applied (wheel
barrow or nut cracker)
3. Class three- Force in middle, fulcrum on one
side and resistance on the other (tweezers)
7. THE INCLINED PLANE
• An inclined plane is a flat surface (ramp) at an
angle to the ground making lifting or lowering
easier.
• Incline planes reduce force required to move
objects by changing the ratio of the distance
the objects travels vs. the height it was
lifted/lowered.
8. THE WHEEL AND AXLE
• This is a wheel connected to an axle (straight
bar) that rotate together.
• A hinge or bearing typically supports the wheel.
• This is a cousin of the lever, as the hinge acts as
the fulcrum.
9. THE SCREW
• The screw is a machine that changes rotational
(round) motion into linear (straight) motion.
• A screw is typically a cylinder with threads
wrapped around it. The screw moves into
another object with or without threads that
match.
• Screws amplify force. The larger the distance
between the threads on the screw, the more
magnified the force.
10. THE WEDGE
• The wedge is a triangular shaped tool that is
essentially a small, transportable inclined plane.
• The wedge is typically used to separate two
objects, lift an object, or hold an object in place.
• Force is applied to the blunt end and then the
force is translated into a perpendicular force to
the plane.
• The longer the wedge the more the mechanical
advantage (although it takes longer).
11. THE PULLEY
• A pulley is a type of wheel and axle that has a
cable/belt/rope/chain running along it’s
circumference in a designated groove.
• There are three main types of pulley systems:
1. Fixed Pulley 2. Moveable Pulley 3. Compound
Pulley
