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Not so simple machines

Not so simple machines. The six hardest working machines in your world. What is a machine?. Machines make work easier. How do machines make work easier?. They can change the amount of force They can change the distance They can also change the direction

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Not so simple machines

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  1. Not so simple machines The six hardest working machines in your world

  2. What is a machine? • Machines make work easier.

  3. How do machines make work easier? • They can change the amount of force • They can change the distance • They can also change the direction • Multiply force which decreases distance the load moves. • Multiply the distance which decreases force. • Or, they leave force and distance alone but change the direction in which the load moves.

  4. What is mechanical advantage? The number of times a machine multiplies the effort or input force.

  5. The Lever

  6. What is a Lever? a rigid bar that is free to turn about a fixed point called the fulcrum Every Lever has three (3) parts: Effort: Where force is placed. Resistance: Object that is moved Fulcrum Pivoting Point

  7. There are 3 types of levers: • A first class lever is like a teeter-totter or see-saw. One end will lift an object (child) up just as far as the other end is pushed down.

  8. A second class lever is like a wheel barrow. The long handles of a wheel barrow are really the long arms of a lever. Picture from http://staff.harrisonburg.k12.va.us/~mwampole/1-resources/simple-machines/wheelbarrow.html

  9. A third class lever is like a fishing pole. When the pole is given a tug, one end stays still but the other end flips in the air catching the fish.

  10. Diagrams of Levers Effort force = input force Load – output force

  11. Examples of Levers • 1st Class – Seesaw, crowbar • 2nd Class – Wheelbarrow, Nutcracker • 3rd Class – Forearm, Rake, Broom

  12. The Pulley

  13. What is a pulley? A rope, belt or chain wrapped around a grooved wheel. Picture from http://discover.edventures.com/images/termlib/f/fixed_pulley/support.gif

  14. Diagrams of Pulleys

  15. Examples of Pulleys • Window Blinds • Flagpole Picture from http://home.howstuffworks.com/home-improvement/repair/how-to-repair-windows4.htm Picture from http://www.engineersaustralia.org.au/careers/engquest/students-lower-sm.cfm?CFID=8384&CFTOKEN=96471203#Load?CFID=8384&CFTOKEN=96471203

  16. The Inclined Plane

  17. What is an inclined plane? A straight slanted surface. ( Ex. a ramp.) Picture from http://staff.harrisonburg.k12.va.us/~mwampole/1-resources/simple-machines/handicap-walk.html

  18. The Inclined Plane Effort Distance Resistance

  19. Examples of an Inclined Plane • Ramp • Stairs Picture from http://staff.harrisonburg.k12.va.us/~mwampole/1-resources/simple-machines/steps.html#answer1

  20. The Screw

  21. What is a screw? An inclined plane that wraps around a shaft. Picture from http://www.nvsd44.bc.ca/sites/ReportsViewOnePopM.asp?RID=3812

  22. Diagram of Screw Picture from http://www.engineersaustralia.org.au/ieaust/app_templates/coretemplates/engquest/images/Machines/SM_diagram12.jpg

  23. The Wedge

  24. The Wedge an inclined plane that tapers to a sharp edge Picture from http://www.engineersaustralia.org.au/ieaust/app_templates/coretemplates/engquest/images/Machines/SM_diagram11.jpg

  25. Examples of Wedges Zipper Door Stop

  26. The Wheel & Axle

  27. The Wheel & Axlea wheel connected to a rigid pole • The Wheel & axle is a modified lever: • The center of the axle acts as a fulcrum – making the wheel a lever that rotates around in a circle.

  28. Examples of a wheel & axle

  29. What type of machine? • http://staff.harrisonburg.k12.va.us/~mwampole/1-resources/simple-machines/

  30. Sources • http://www.science-class.net/PowerPoints/Types%20of%20Simple%20Machines.htm • http://www.science-class.net/PowerPoints/Work_Simple_Machines.htm

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