The moment is the turning effect of a force.
moment about O = F l
| where: | |||
symbol |
description |
type |
units |
| moment | effort | bivector | Nm=newton-metre=kg*m2/s2 |
| F | Force | vector | N=newton=kg*m/s2 |
| l | perpendicular distance from pivot | vector | m |
moment = F y
A moment is a force multiplied by the perpendicular distance from a pivot or falcrum, the units of a moment are Newton-metres (N m). For equilibrum:
moments clockwise = moments anticlockwise
Example
Find the reactions of the beam shown:
Take moments about R1, for equilibrium,
moments clockwise = moments anticlockwise
2500*1 + 5000*7 = R2*10
R2 = 3750N
forces acting down = forces acting up
2500 + 5000 = R1 + 3750
R1 = 3750 N
