How Do Forces and Couples Work in Physics?

[robm]

Please find the attachment below. Thanks

 

[radou]

In such an example it is extremely useful to calculate the resultant force in a graphical way using the simple rules of vector addition. Further on, use the fact that, if two forces (i.e. the lines on which their vectors are placed) meet at a point A, then their resultant must be placed at A (i.e. the line of the resultant must contain the point A). In the end, it may be useful to mention that you can replace a concentrated moment with a couple of forces (parallel) whose magnitudes are equal, but are pointing in opposite directions. The product of the distance of these two forces and the magnitude of any of them must equal the magnitude of the concentrated moment. Use these facts and try to work something out. If you get stuck, it may be useful to present your work.

Btw, take a look at the 'Statics' section at this link, it should be useful: http://www.fsid.cvut.cz/en/U2052/node1.html".