lever systems Flashcards
what is the first class lever
the load and effort are at opposite ends of the lever and the fulcrum is in the middle eg tilting your head
what is the second class lever
the fulcrum and effort are at opposite ends of the lever the load is in the middle eg standing on your toes
what is the third class levers
the fulcrum and load are at opposite ends of the lever. the effort is in the middle eg flexion at the elbow
what is a lever
a lever is a solid bar that moves about a fixed point when a force is applied to it
what is the effort
the force is applied by the muscle to the lever arm (arrow)
what is the fulcrum
the joint where the lever arm pivots (triangle)
what is the load
the resistance against the pull of the muscles on the lever arm (sqaure)
why can a lever have a mechanical advantage
if the distance from the fulcrum to the effort is greater than the distance from the fulcrum to the load the lever has a mechanical advantage
how can a second class lever have a mechanical advantage
the effort is further from the fulcrum than the load is
how can a first class lever has a mechanical advantage
if the fulcrum is closer to the load than the effort
why do third class levers has a mechanical disadvantage
the distance from the fulcrum to the effort is always less than the distance from the fulcrum to the load
why do first class levers have a mechanical disadvantage
fulcrum is closer to the effort than it is to the load
