Statics - Balancing moment and resultant force

[lax1113]

Homework Statement

Replace the force system with a resultant and specify where its line of action intersects AB from point B.

so I guess the imagine didn't work...
http://yfrog.com/htstaticspicp

I realize it is very small I apologize for that, if anything in the picture is unclear please let me know.

Homework Equations

Fresultant = sum of Forces
Moment = sum of Moments

The Attempt at a Solution

I have solved the components of the X and Y forces of each of the 3 forces and got a resultant of 542N and also got the angle of inclination of this resultant, as 10.6 degrees. However, I am not getting the right answer when I sum the moments. Since it wants where this would be along AB, I set up my moment equation as 533N (the y portion of F resultant) * y = {sum of all of the moments that are acting perpendicular to the line segment AB}. However, I am not getting the correct answer? Is this the right way to go about this problem?

 

[tiny-tim]

Hi lax1113!

I think you're missing that there's a resultant (linear) force and a couple (a disembodied moment).

The moment of the couple is the same about any point, and you'll need to subtract it before you can find the line of the resultant (linear) force.