What The Different Types Of Lever Present?

A lever is a rigid rod pivoted at a fixed point, the fulcrum. It is able to move about this point under the action of opposing forces. Bones, especially the long bones, are like rigid rods capable of moving against another bone at a joint (the fulcrum) under the pull of muscles. The skeleton can therefore be considered as comprising a series of levers.Three orders of levers are recognized by physicists. Examples of these levers can be found in everyday life and also within the animal body.

First order levers: Consider a rigid rod pivoted at a fixed point. In order to lift a load attached to one end of the rod, a pull of effort must be applied. Such a lever with the fulcrum situated between the load and the effort is a first order lever Second order levers: In this order of levers the load lies between the fulcrum and the effort. Examples in everyday life are the nutcracker and the wheelbarrow.

Third order levers: In third order levers the effort is between the load and the fulcrum. Examples in everyday life are forceps and ice tongs; in the animal body, the bending of the elbow by the contraction of the biceps muscle.