# Force Help Needed

1. Oct 7, 2012

### iMAGICIALoTV

1. The problem statement, all variables and given/known data

2. Relevant equations
I don't know if I set the equation for horizontal component of the bigger block correctly:

$\huge{\Sigma F_{x_1} = F_a - (f_k + N_2) = ma}$

If this is true then it seems that there is not enough given information to find $F_a$. Are there some other way?

3. The attempt at a solution
Find the normal force and friction, then substitute some variables, I guess? I got 6.877 N, but I know it's wrong...

2. Oct 7, 2012