Transcript 6 simple machines (science), jack

6 Simple Machines
By: Emma Dillon
Miles Taylor
Jack Yau
Kevin Lynch
Table of Contents
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Simple Machines
Compound Machines
Inclined Plane
Wedge
Screw
Lever
Wheel and Axle
Pulley
More Videos
Acknowledgments (resources)
Simple Machines
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by: Emma Dillon
There are six basic machines; the inclined
plane, wedge, screw, lever, wheel and axle,
and the pulley.
Simple Machines Video
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Compound Machines
by: Miles Taylor
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A compound machine is a machine that
consists of two or more simple machines.
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Example: Bicycle. It has a pulley for the bike
chain, two wheels and axles, levers for the
hand brakes, and screws to hold it together.
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Inclined Plane
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by Emma Dillon
An inclined plane is a flat slanted surface
whose endpoints are at different heights.
An inclined plane lets you exert your input
force over a larger distance. That way, the
input force will be less than the output
force.
How to determine the ideal mechanical
advantage of an inclined plan:
Length of incline
_______________ = ideal mechanical advantage
Height of incline
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More Information
Uses:
 You use it to lift objects
from lower levels to
higher levels.
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An example is a ramp.
Values:
 One value of the
inclined wedge is that it
reduces work due to
friction.
 You increase the
efficiency of an inclined
plane by decreasing the
friction.
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Wedge
by: Emma Dillon
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A wedge is a device that is thick at one end and
tapers to a thin edge at the end.
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Wedges are inclined planes two of them back to
back that can move.
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The longer and thinner the wedge, the less input
force is required to do the same amount of work.
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In a wedge, instead of an object moving along the
inclined plane, the inclined plane moves itself.
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How to determine the mechanical advantage of the
wedge:
Length of sloping side =mechanical advantage
Length of thick end
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More Information
Uses:
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A wedge uses force to come
between two objects.
It is used for three different
types of work: splitting,
connecting, and tightening.
Examples of wedges are
axes, nails, doorstops, and
zippers.
Values:
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There are many values of
the wedge.
When using a wedge, a
small force is multiplied to
do the job. This is good
because it reduces the
amount of the input force,
the force that you have to
put in.
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Screws
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A simple machine that is related to the inclined
plane.
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It can be thought as an inclined plane wrapped
around a cylinder.
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When you use a screwdriver to twist a screw into
a piece of wood, you are exerting an input force
on the screw.
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When you turn the screw into the wood, the
screw exerts an output force on the wood.
The mechanical advantage of a screw can be
found by dividing the circumference of the screw
by the pitch of the screw.
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by: Jack Yau
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Levers
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A lever is a rigid bar that is free to pivot, or
rotate, about a fixed point.
The fixed point that a lever pivot around is
called the fulcrum.
Think about a lever like a paint can opener, the
opener is resting against the edge of the can
acts, as a fulcrum. The tip f the opener is under
the lid of the can. You push down on the opener,
exerting an input force, and the opener pushes
the lid up, exerting an output force on the lid.
To calculate the ideal mechanical advantage ,
you have to divide the distance from fulcrum to
input force by distance from fulcrum to output
force.
by: Jack Yau
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History of Wheels
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by: Kevin Lynch
The English word wheel comes from the Proto-IndoEuropean *kwekwlo-,[1] which was an extended form
of the root *kwel- meaning "to revolve, move around".
This is also the root of the Greek κυκλος kuklos, the
Sanskrit chakra, and Persian charkh, all meaning
"circle" or "wheel",[2] and also in Lithuanian, sukti
means "to rotate". The Latin word rota is from the
Proto-Indo-European *rotā-, the extended o-grade
form of the root *ret- meaning "to roll, revolve".[3]
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History of Axle
History of Axle
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by: Kevin Lynch
An axle is a central shaft for a rotating wheel or gear.
In some cases the axle may be fixed in position with a
bearing or bushing sitting inside the hole in the wheel
or gear to allow the wheel or gear to rotate around the
axle. In other cases the wheel or gear may be fixed to
the axle, with bearings or bushings provided at the
mounting points where the axle is supported.
Sometimes, especially on bicycles, the latter type is
referred to as a spindle.
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Wheels (cont.)
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Ideal MA= radius of wheel/ radius of axle
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Actual MA= R/E actual
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Screwdrivers, doorknobs, windmills, gears,
and Chain Falls are all examples of the wheel
and axle.
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History of levers
by: Kevin Lynch
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First class levers: A first-class lever is a lever in which
the fulcrum is located in between the input effort and the
output load.
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Second class levers: In a second class lever the input
effort is located at one end of the bar and the fulcrum is
located at the other end of the bar, opposite to the input,
with the output load at a point between these two forces.
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Third class levers: It is to be noted that for this class of
levers, the input effort is higher than the output load,
which is different from the first-class and second-class
levers.
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History of the Axle
Facts About Levers
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Lever: In physics, a lever (from French lever,
"to raise", c.f. a levant) is a rigid object that is
used with an appropriate fulcrum or pivot
point to multiply the mechanical force that can
be applied to another object. This is also
termed mechanical advantage, and is one
example of the principle of moments. A lever
is one of the six simple machines.
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More on Wheels
The Pulley
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by: Miles Taylor
The pulley is a machine that consists of one or more wheels with
grooves, and rope.
To operate the pulley, put the rope in the groove and hang the wheel
on something. Now apply downward pressure, or pull on the rope.
The rope on the other side should raise, along with whatever it is
attached to.
There are many different kinds of pulleys- fixed pulleys, movable
pulleys, and compound pulleys. Fixed pulleys are when the wheel
doesn’t move, a movable pulley is when the wheel does move, and a
compound pulley is when there are multiple wheels.
The mechanical advantage of the fixed pulley is 1.
The machanical advandahe of the movable pulley is 2
For compound pulleys, add the multiple for each wheel. For
instance. 2 wheels: 2. 3:3. 4:4 and so on…
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More Videos
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http://youtube.com/watch?v=C-UXry70iXM
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http://youtube.com/watch?v=sOikTpFgi3Y
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Information Resources
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Science Explorer; Motion, Forces, and Energy ---(information
on the wedge and inclined plane)
http://www.fi.edu/pieces/knox/automaton/wedge.htm --(information on the wedge)
http://en.wikipedia.org/wiki/Wedge_(mechanics) --(information on the wedge’s mechanical advantage)
http://en.wikipedia.org/wiki/Wheel#History_of_the_wheel_an
d_axle
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Picture Resources
Picture Resources
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Inclined plane:
More Resources
http://images.google.com/imgres?imgurl=http://physics.kenyon.edu/EarlyAppa
ratus/Mechanics/Inclined_Plane/ebay1.JPG&imgrefurl=http://physics.kenyon.
edu/EarlyApparatus/Mechanics/Inclined_Plane/Inclined_Plane.html&h=325&
w=450&sz=20&hl=en&start=2&tbnid=Jb2q2Nrei7LfCM:&tbnh=92&tbnw=1
27&prev=/images%3Fq%3Dinclined%2Bplane%26gbv%3D2%26svnum%3D
10%26hl%3Den
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Second Inclined Plane:
http://www.blueberryforest.com/images/Images_ct/kinderkram-40513-ramp389.jpg
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Wedge Picture:
http://www.ed.uri.edu/SMART96/ELEMSC/SMARTmachines/images/wedge.j
pg
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Zipper Picture: http://www.wpclipart.com/clothes/zipper_2.png
Ax and Nail Picture: Clip Art
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Picture Resources (Cont.)
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Screw Picture: http://www.artestuff.com/images/screw-standard.jpg
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Lever Picture: http://www.sciencebyjones.com/Firce_class_lever_drawing.gif
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Bike Picture: http://weightweenies.starbike.com/images/lightbike/bike.jpg
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Simple Machines Pictures:
Pulley; http://www.indiainnovates.com/images/products/pulley_stopper.jpg
Wedge; http://www.brantacan.co.uk/WedgeActionMW.gif
Inclined Plane;
http://dots.physics.orst.edu/graphics/image_maps/inclined_plane.gif
Lever; http://www.techsploration.com/Lever2.JPG
Screw; http://faq.f650.com/FAQs/Photos/ChainPhotos/ChainGuardScrew.jpg
Wheel and Axle;
Back
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http://www.ed.uri.edu/SMART96/ELEMSC/SMARTmachines/images/logo.gif