# More Moments 3D

- Author:
- Dr. Doug Davis, 3D

## Description

Shown are a position vector , , a force vector , , and the resulting moment vector , . Moving the red dot will change the force and the blue dot changes the position.

## Task

After familiarization with the controls. Note: For a selected point the crossed arrows indicate you can move the point parallel to the xy plane and the opposing arrows indicate you can move the point parallel to the z-axis.
, and another component of the force perpendicular to . Note that is the magnitude of the projected vector and is the unit direction vector of and the vector dot product is also shown. Looking at the result how would the moment of differ from the moment and what would be the result of .
is the new position vector which is shown at the top as r. An angle between the position and force vectors is also shown along with the length of the r is the moment of the force about the axis OL. The moment arm (position vector) is from a point on the axis to the application point of the force. This point can be moved with the slider. How does vary with the position of the point? Also shown is the length of the moment arm and an angle between the axis and the moment arm. At what angle is the moment arm length minimum?

- Check Projection

- Check Line Of Action

_{1}vector. At what angle is the length of r_{1}a minimum?- Check Moment about an Axis