1. By: John Breslin Sarah Kravinsky Zoe Adler Neal Khaisman

2. Table of Contents Levers Screws Inclined plains Pulleys Wedges Wheels and Axel Resources

3.  A rigid bar that rotates around a fixed point  The fixed point is a fulcrum  IMA = distance from fulcrum to input force÷ distance from fulcrum to output  3 different types of levers- 1 class, 2 class, 3 class What are levers? Back To Table of Contents

4.  A screw is sometimes considered an inclined plane wrapped around a cylinder  The closer together the threads are, the greater the MA  Examples: bolts, screws, faucets, jar lids What are screws? Back to Table of Contents

5. A pulley is a grooved wheel with a rope,chain, or steel cable wrapped around it.  A pulley is used by pulling on the rope, chain, or cable around it.  A pulley makes work easier by changing the amount and direction of your input force.  Pulleys are used to lift large masses onto tall structures. Did you know? Pulleys are also called blocks and sheaves. What are pulleys? Back to Table of Contents

6.  A flat, slanted surface  Allows you to exert a force over a longer distance  Ideal mechanical advantage= length of incline/ height of incline  Example situation: A box is too heavy to lift from one level to another. To increase the distance over which you are pulling it, you set up a ramp. It is now easier to pull the box up to the higher level. What are inclined planes? Back to Table of Contents

7.  Wheels and axles, such as those on carts, reduce resisting force by distributing it throughout the wheel or axle, and therefore make it easier to haul loads.  The formula for finding the mechanical advantage of a wheel and axle is the ratio of the radius of the wheel to the radius of the axle.  Watch a video about wheels! Watch a video about wheels! What are wheels and axels? Back to Table of Table of ContentsContentsTable of Contents

8.  A device that combines two or more simple machines.  To find out the ideal mechanical advantage of a compound machine, you must know the mechanical advantage of each simple machine.  Example: a mechanical pencil sharpener. When turning the handle, you are using a wheel and axel. The two wheels inside are screws that whittle away at the pencil, making it sharp. What are compound machines? BackTable of Contents to Table of ContentsTable of Contents

9.  http://en.wikipedia.org/wiki/Pulley http://en.wikipedia.org/wiki/Pulley  http://library.thinkquest.org/27948/pulley.html http://library.thinkquest.org/27948/pulley.html  Science explorer science textbook  http://images.google.com/imgres?imgurl=http://en cyclozine.com/Science/Physics/Machines/incline.g if&imgrefurl=http://encyclozine.com/Science/Physi cs/Machines/&h=197&w=316&sz=3&hl=en&start= 8&um=1&tbnid=JdnWB- 9PPRsgiM:&tbnh=73&tbnw=117&prev=/images%3 Fq%3Dinclined%2Bplane%26svnum%3D10%26u m%3D1%26hl%3Den%26sa%3DN Resources Back to Table of Contents