ECHANISMS: Lever
A lever is a simple machine consisting of a rigid rod that can rotate around a foothold. This bar will a point of application of force (F), and point of application of the resistance (R). To resolve a lever in equilibrium we use the term so-called law of the lever F × d = R * R
where d is the distance from the point of application of force to the fulcrum, and r the distance fulcrum to the point of application of resistance.
As the relative position of the fulcrum for F and R are three types of levers.
1 .- The 1 grade that has the fulcrum between the force and resistance,
2 .- The grade 2 which has the resistance between the fulcrum and the force and
3 .- The 3-grade having the force between the fulcrum and the resistance