Moment of a force: Part 1

 

The magnitude of the moment of a force:

MO: Magnitude of the moment of F around point O

d: Perpendicular distance from O to the line of action of F

 

 

 

 

Note: moving a force along its line of action does not change its moment

Note:

 

Direction of the moment in 2-D: The direction of the moment is given by the right hand rule: Counter Clockwise (CCW) is out of the page, Clockwise (CW) is into the page.

Calculating the moment in 2-D using components: Moments add together as vectors. Select a positive direction (CCW or CW), then calculate each moment and add them using the proper sign for each term. For example:

 

 

 

 


Mehrdad Negahban and the University of Nebraska, 1996-2006.

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Copy and distribute freely for personal use only

 

Department of Engineering Mechanics, University of Nebraska, Lincoln, NE 68588-0526