Jason Day 1

 A lever is an object consisting of a rigid bar or plank that pivots at a certain point. Often used to lift an object at a second point when applying force to a third point. 2

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TThe first point (where the bar or plank pivots) that is called the “fulcrum.” TThe second point (the fraction of the bar or plank holding up the object that is to be lifted) is called the “resistance arm.” TThe third point (the fraction of the bar or plank that force is applied to) is called the “effort arm.” 4

Resistance Arm Effort Arm Fulcrum Object Bar or Plank Applied Force Pivot 5

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MMechanical advantage is the ratio of output force to the input force. IIt is used to calculate the efficiency of a machine. TThe higher the number the more efficient the machine is. The lower the number the less efficient the machine is. 8

TThere are three different types of levers. AA first class-when the fulcrum is in between the where the force is applied and the object or load. AA second class-when the object or load is in between the pivot and where the force is applied. AA third class-when the point at which the force is applied is between the object or load and the pivot. 9

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AA see saw AA pair of scissors PPliers 11

 A stapler  A wheel barrow  A nail clipper 12

 Tweezers  Fishing Rod  Tongs 13

 Levers are used to move object. Usually.  Levers can be found in many different places.  To calculate Mechanical Advantage of a lever you divide the length effort arm from the length resistance arm. (see page 6)  There are different of levers. First Class, Second Class, and Third Class. (see pages 10-13) 14