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Making WORK easier!. Types of Simple Machines. Pulley. Inclined Plane. Lever. Wheel and axle. Wedge. Screw. Why do we use them?. Machines make work easier (NOT less) by changing either the:. Size of the force. Direction of the force. 50 kg. Mechanical Advantage. - PowerPoint PPT Presentation
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Making WORK easier!Making WORK easier!
Types of Simple MachinesTypes of Simple Machines
LeverLever
ScrewScrewWedgeWedge
Inclined PlaneInclined PlanePulleyPulley
Wheel and Wheel and axleaxle
Why do we use them?Why do we use them?
Machines make work easier (NOT less) by Machines make work easier (NOT less) by changing either the:changing either the:
Direction of the forceDirection of the forceSize of the forceSize of the force
50 kg
Mechanical AdvantageMechanical AdvantageThe number of times a machine multiplies your The number of times a machine multiplies your
applied force is the ACTUAL mechanical advantgeapplied force is the ACTUAL mechanical advantge
M.A. = Fr
Fe
Resistance Resistance Force (weight Force (weight of object)of object)
Effort Force Effort Force (force YOU are (force YOU are supplying)supplying)
Mechanical Mechanical AdvantageAdvantage
Effort ForceEffort Force
FFee
Resistance ForceResistance Force
FFrr
Ideal Mechanical AdvantageIdeal Mechanical Advantage
The number of times a machine SHOULD The number of times a machine SHOULD multiply your applied forcemultiply your applied force
I.M.A. = I.M.A. = depends on type of depends on type of machinemachine
Ideal Mechanical Ideal Mechanical AdvantageAdvantage
Measure of how much work put into aMeasure of how much work put into a
machine is changed to useful work put outmachine is changed to useful work put out
by the machine.by the machine.
M.A.
I.M.A.Efficiency = X 100
EfficiencyEfficiency
WorkWork
Energy is conserved Energy is conserved in “ideal” in “ideal” machines, the work you put in is equal to machines, the work you put in is equal to the work the machines gives outthe work the machines gives out
““Real” machines Real” machines you do MORE work you do MORE work than machines give back outthan machines give back out
Why use them???Why use them???
W = FW = F··dd W = W = FF··dd
Parts of a leverParts of a lever
Fr
Feddrr
ddeeFulcrumFulcrum
Resistance distanceResistance distance
Effort distanceEffort distance
Three classes of LeversThree classes of Levers11stst class lever class lever 22ndnd class lever class lever
33rdrd class lever class lever
Mechanical Mechanical Advantage is Advantage is LESSLESS than 1 than 1
FulcrumFulcrum
Effort ForceEffort Force
Resistance Resistance ForceForce
Which class lever?Which class lever?
IMA - LeversIMA - Levers
The number of times a lever SHOULD The number of times a lever SHOULD multiply your applied forcemultiply your applied force
I.M.A. = dI.M.A. = dee
ddrr
Resistance Resistance distancedistance
Effort Effort distancedistance
Inclined planeInclined plane
FFrrFe
WWoutout = = FFrr··ddrr
WWinin = = FFee··ddee
Ideal Mechanical Advantage - Ideal Mechanical Advantage - Inclined PlaneInclined Plane
IMA = LIMA = L
hhLL
hh
Big Bang Theory clip
Works CitedWorks Citedhttp://www.uen.org/utahlink/activities/uploads/6528_a_screw.jpghttp://www.beth.k12.pa.us/schools/wwwclass/mcosgrove/simplemachines.gifhttp://www.school-for-champions.com/science/images/machines4.gifhttp://www.ent.ohiou.edu/~bobw/html/HapEd/NASA/SimpMach/cl2lever.gifhttp://library.thinkquest.orghttp://www.the-office.com/summerlift/pulley1.gifhttp://encyclozine.com/Science/Physics/Machines/incline.gifhttp://www.fi.edu/pieces/knox/automaton/images/thewedge.gifhttp://www.worsleyschool.net/science/files/wheel/diagram1.gifhttp://www.metro-region.org/imageRepository/ACFQWB8ebaLm.gifhttp://www.ccohs.ca/images/MMH136.gifhttp://www.dynamicscience.com.au/tester/solutions/hydraulicus/animatedfourpulley.gifhttp://juniorengineering.usu.eduhttp://www.technologystudent.com/images3/lpulle23.gifhttp://www.technologystudent.com/images3/lpulle23.gifhttp://www.sciencebuddies.org/mentoring/project_ideas/ApMech_img007.jpghttp://www.sciencebuddies.org/mentoring/project_ideas/ApMech_img007.jpghttp://www.gutenberg.org/files/16593/16593-h/images/image_110.jpghttp://www.gutenberg.org/files/16593/16593-h/images/image_110.jpghttp://discover.edventures.com/images/termlib/s/screw/support.gifhttp://discover.edventures.com/images/termlib/s/screw/support.gifhttp://selland.boisestate.edu/jbrennan/physics/images/http://selland.boisestate.edu/jbrennan/physics/images/http://members.aol.com/crummybut/splittingwood.jpghttp://members.aol.com/crummybut/splittingwood.jpg
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