I need to solve for the mass of block C that is in the verge of slipping. All surfaces have a coefficient of static friction of 0.11. The cable connecting the wedge B and C is parallel with the incline. I have given for the mass of the wedges A and B.
I have established the FBD and its initial equations but I am not sure if it is correct.
For wedge A,
The initial equations are $\sum F_x = F_1(cos20) + N_1(sin20) - F_2(cos40) - N_2(sin40) = 0$ and $\sum F_y = W_A - F_1(sin20) + N_1(cos20) - F_2(sin40) + N_2(cos40) = 0$
For wedge B,
The initial equations are $\sum F_x = F_3 + F_2(cos40) + N_2(sin40) + T(cos11) = 0$ and $\sum F_y = -W_B - T(sin11) + F_2(sin40) - N_2(cos40) = 0$
For block C,
My initial equations are $\sum F_x = -T - W_C(sin11) - F_4 = 0$ and $\sum F_y = N_4 - W_C(cos11) = 0$
I will edit my illustration for my tension here. I think it is wrong.
Did I miss something in the cases of friction? Are those all I need to solve for the mass of block C?