ES-70 Moments About a Point

The moment about a point is defined as shown here where - unit vector perpendicular to (the position vector) and (the force) following the right hand rule.

The geometric configuration is demonstrated here.

    M = (ry·Fz - rz·Fy)i
        - (rx·Fz - rz·Fx)j
        + (rx·Fy - ry·Fx)k
The moment may be given in component form as shown where rx, ry and rz are the component of the position vector r and Fx, Fy and Fz are the components of the force vector F.

For example, if is applied at the location specified by as specified here...

... then the moment can be calculated as shown here.
Copyright ©2000 B2 Group