# Mechanical Advantage - Law of Lever

## Description

Mechanical advantage is a measure of the force amplification achieved by using a tool, mechanical device or machine system. Ideally, the device preserves the input power and simply trades off forces against movement to obtain a desired amplification in the output force.If a and b are distances from the fulcrum to points A and B and if force FA applied to A is the input force and FB exerted at B is the output, the ratio of the velocities of points A and B is given by a/b, so the ratio of the output force to the input force, or mechanical advantage, is given by:

Related formulas## Variables

F_{B} | output force applied to point B (N) |

F_{A} | input force applied to point A (N) |

a | distance from the fulcrum to point A (m) |

b | distance from the fulcrum to point B (m) |