Replace the two couples shown with a single equivalent coupl

Replace the two couples shown with a single equivalent couple, specifying its magnitude and the direction of its axis. Solve Prob. 3.76, assuming that two 10-N vertical forces have been added, one acting upward at C and the other downward at B. If P = 0, replace the two remaining couples with a single equivalent couple, specifying its magnitude and the direction of its axis.

Solution

From the calculation,

The two 50 N forces are separated by distance of 96mm Therefore the couple acting is 4.8N-m and is acting in the anti clockwise direction when viewed from the surface ABCD.

The two 125N forces are separated by a distance of 192mm. Therefore the couple acting is 24N-m and it is acting clockwise direction from viewed from the top.

The two 10 N forces are separated by adistance of 160mm. Therefore the couple acting is 1.6 N-m and it is acting clockwise from the front end.