Transcript Simple Machines - Pulley, Wedge, Screw

Making WORK easier!
Types of Simple Machines
Lever
Wedge
Pulley
Screw
Big Bang Theory clip
Inclined Plane
Wheel and
axle
Ideal Mechanical Advantage - Pulley
I.M.A. = number of rope sections
pulling upwards
IMA = 1
IMA = 2
IMA = 1
Changes direction of force so
the work is easier (you are
now working with gravity
instead of against it)
IMA = 2
Multiplies the force
by 2 so that you can
lift something twice
as heavy as you pull.
Single Fixed
Pulley
Movable Pulley
IMA = 2
IMA = 1
What is the IMA of the following
pulley system?
25%
25%
25%
2
3
25%
1. 1
2. 2
3. 3
4. 4
1
4
What is the IMA of the following
pulley system?
20%
20%
20%
2
3
20%
20%
1. 1
2. 2
3. 3
4. 4
5. 5
1
4
5
Inclined plane
Wout =
Win = Fe·
Fr·
de
Fr
dr
Ideal Mechanical Advantage Inclined Plane
Big Bang Theory clip
IMA = L
h
L
h
Wheel and axle
I.M.A. = radius of wheel
radius of axle
Wedge
Two sloping sides – changes direction of
the force
Screw
A wedge with an inclined plane wrapped
around it
More turns = higher mechanical advantage
Frayer Model
Examples:
Non-examples:
See-saw
Wheelbarrow
Crowbar
Rake
1st class levers
Essential
Characteristics:
Effort force, Resistance
force, and fulcrum present.
Fulcrum is between effort
force and resistance force.
Non-essential
Characteristics:
Mechanical advantage is
one or more.
Makes work easier by
multiplying the force.
Frayer Model
Examples:
Non-examples:
Inclined Planes
Essential
Characteristics:
Non-essential
Characteristics:
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