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Work and Machines
Simple Machines
Work and Machines
Machines make work easier to do– They change the size of a force needed,
the direction of a force, or the distance over which a force acts
Work and Machines
Work Input and Work Output– Because of friction, the work done by a
machine is always less than the work done on the machine
Work and Machines
Work Input to a Machine– Input force- the force you exert on a
machine – Work input- the work done by the input
force acting through the input distance
Work and Machines
Work Output of a Machine– Output force- the force that is exerted by a
machine– Output distance- the distance the output
force is exerted through– Work output- the output force multiplied by
the output distance
Simple Machines
Six types of simple machines:– Lever– Wheel and Axle– Inclined Plane– Wedge– Screw – Pulley
Simple Machines
Lever- a rigid bar that is free to move around a fixed point– Fulcrum- the fixed point the bar rotates
around
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http://visual.merriam-webster.com/science/physics-mechanics/lever.php#bar32386
Simple Machines
Wheel and Axle- consists of two disks or cylinders, each one with a different radius
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http://en.wikipedia.org/wiki/Wheel_and_axle
Simple Machines
Inclined Plane- a slanted surface along which a force moves an object to a different elevation
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http://homeschooling.about.com/od/freeprintables/ss/machinecolor.htm
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http://www.springboardmagazine.com/science/simplemachines.htm
Simple Machines
Wedge- a v-shaped object whose sides are two inclined planes sloped toward each other
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http://www.sciencephoto.com/media/83826/enlarge
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http://www.newagearbor.com.au/shop/prod334.htm
Simple Machines
Screw- an inclined plane wrapped around a cylinder
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http://en.wikipedia.org/wiki/File:GearBoxRotLinScrew.gif#filelinks
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http://en.wikipedia.org/wiki/Screw_(simple_machine)
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http://www.b2bscrews.com/furniture-screw.htm
Simple Machines
Pulley- consists of a rope that fits into a groove in a wheel
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http://www.sparknotes.com/testprep/books/sat2/physics/chapter8section2.rhtml
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http://science.howstuffworks.com/transport/engines-equipment/pulley.htm
Simple Machines
Compound Machine- any combination of two or more simple machines
