Answer:42.57x 10^7 N/mm2
Step-by-step explanation:
The normal stress is derived in a body that is under tension and is calculated by taking the ratio of axial force applied on the body to the cross-sectional area of that same body. 
Therefore, 
The dimensions are 1/16 x 1/4
Let the force along AC be Fac then stress at AC will be 
Phi (N) = Fac / A 
Fac Cos 30 degrees x (.175m + .075m) x 960 = equilibrium of moment about point B. 
Therefore 
Phi N = 665.127(N) / (1/16x 1/4)
Therefore normal stress at the centre of link AC = 42.57 x 10^3 N/mm2