# Equivalent force and couple moment

Tags:
1. Aug 13, 2017

### marsupial

1. The problem statement, all variables and given/known data
I will post a photo of the question in the thread once I've created it. I have found the magnitude and angle of the resultant force, but I am unsure of how to proceed. I find moments and couples confusing.

2. Relevant equations

$$\vec M = \vec r \times \vec F$$

3. The attempt at a solution

So, to find $\vec r$ I chose a point on $\vec F$ (1, 0.8069) (call it C), and calculated $r_{BC}$: $r_{c} = -7i + 0.8069j$. Then I took the cross product of r and F, and got 41.58kN.m, but this is incorrect, and I am stumped.

2. Aug 13, 2017

### marsupial

3. Aug 14, 2017

### marsupial

i found the answer, thanks.