One force of magnitude 5 N keeps the member in equilibrium w

One force of magnitude 5 N keeps the member in equilibrium while it is subjected to other forces acting in the plane (shown schematically at the bottom). The three dots denote equally spaced points along the member. Assuming the other forces stay the same, what load(s) could replace the 5 N force and maintain equilibrium?

Solution

The applied force of 5N at the third dot, produces a push of 5N and a moment of 5x40 = 200N-mm about the central dot.

The depiction (e) shows a push of 5N and a moment of 200N-mm about the central dot equivalent to the above.

Depiction (b) also is an equivalent system of forces.