[First Year Statics] Replace Force System

[lc99]

Homework Statement

Homework Equations

The Attempt at a Solution

[/B]
the force resultant = (100i +620j +800k) = 379 N
moment result is (100i-620j+800k) = 1017 which is not correct!

I calculated the moment of all forces about point O using cross product so...

(-3i + 2j) x (-200j) + (-3i +2j) x (-400i) +(3i +0.5k) x (120i +160k)

But, somehow, I am not getting 590 N*m which is the correct answer

 

[scottdave]

Where are you getting (-3i + 2j)? There is no force present at that point