# Moment

Written by Jerry Ratzlaff on . Posted in Classical Mechanics

In physics & engineering, a moment, abbreviated as M, is the tendency to cause a body to rotate around an axis.  It is quantified by measuring force acting on the body and the distance from the axis.  When the moment exceeds the moment required to keep it in place, motion is developed.  In engineering statics, one of the fundamental principals is the sum of the moments about a point equal zero and there is no change in motion;  the body is in static equilibrium.  In engineering dynamics, the sum of the moments about a point is equal to the mass times the acceleleration

 $$\large{ M = F \; d }$$ Where: $$\large{ M }$$ = moment $$\large{ F }$$ = force $$\large{ d }$$ = length of arm Solve for: $$\large{ F = \frac {M}{d} }$$ $$\large{ d = \frac {M}{F} }$$

## Moment Arm

The distance from the pivot point to the point where the force occurs.

Tags: Equations for Force