How does a lever work? Section 5-3 Levers A lever is a bar that is free to turn about a fixed point called the fulcrum which supports the lever. A lever increases force and makes the work easier. Every lever has an effort arm ( dist. from effort force to fulcrum) and a resistance arm (dist. from resistance force to fulcrum). MA = effort arm length/resistance arm length.
Mechanical Advantage MA = effort armlength/resistancearm length. First-class levers The fulcrum is between the effort and the resistance. Crowbar, hammer, scissors. First-class levers Second-class levers The resistance isbetween the effortand the fulcrum.Wheel barrel, bottleopener, nut cracker. Second-class levers Third-class levers The effort isbetween thefulcrum and theresistance. Bat,fishing pole, tennisracket, tweezers,shovel. Third-class levers H.W. p.81 check/apply 1-8 wkst. 5-3 p. 81 activity lever lab