190 likes | 446 Views
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.
E N D
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
Mechanical Advantage The number of times a machine multiplies your applied force is the ACTUAL mechanical advantge Resistance Force (weight of object) M.A. = Fr Fe Effort Force (force YOU are supplying) Mechanical Advantage
Resistance Force Fr Effort Force Fe
Ideal Mechanical Advantage The number of times a machine SHOULD multiply your applied force I.M.A. = depends on type of machine Ideal Mechanical Advantage
Efficiency Measure of how much work put into a machine is changed to useful work put out by the machine. M.A. I.M.A. X 100 Efficiency =
Work • Energy is conserved in “ideal” machines, the work you put in is equal to the work the machines gives out • “Real” machines you do MORE work than machines give back out • Why use them??? W = F·d W = F·d
Parts of a lever Fe dr Resistance distance Fr de Fulcrum Effort distance
Three classes of Levers 2nd class lever 1st class lever 3rd class lever
3rd class lever Fulcrum Effort Force Mechanical Advantage is LESS than 1 Resistance Force
IMA - Levers • The number of times a lever SHOULD multiply your applied force I.M.A. = de dr Effort distance Resistance distance
Fe Fr Inclined plane Wout = Fr·dr Win = Fe·de
Ideal Mechanical Advantage - Inclined Plane IMA = L h Big Bang Theory clip L h
Works Cited http://www.uen.org/utahlink/activities/uploads/6528_a_screw.jpg http://www.beth.k12.pa.us/schools/wwwclass/mcosgrove/simplemachines.gif http://www.school-for-champions.com/science/images/machines4.gif http://www.ent.ohiou.edu/~bobw/html/HapEd/NASA/SimpMach/cl2lever.gif http://library.thinkquest.org http://www.the-office.com/summerlift/pulley1.gif http://encyclozine.com/Science/Physics/Machines/incline.gif http://www.fi.edu/pieces/knox/automaton/images/thewedge.gif http://www.worsleyschool.net/science/files/wheel/diagram1.gif http://www.metro-region.org/imageRepository/ACFQWB8ebaLm.gif http://www.ccohs.ca/images/MMH136.gif http://www.dynamicscience.com.au/tester/solutions/hydraulicus/animatedfourpulley.gif http://juniorengineering.usu.edu http://www.technologystudent.com/images3/lpulle23.gif http://www.sciencebuddies.org/mentoring/project_ideas/ApMech_img007.jpg http://www.gutenberg.org/files/16593/16593-h/images/image_110.jpg http://discover.edventures.com/images/termlib/s/screw/support.gif http://selland.boisestate.edu/jbrennan/physics/images/ http://members.aol.com/crummybut/splittingwood.jpg