ok think I've sussed it:
300,000,000 x ∏ x 0.004^2 x 12 = 180,955 = max force
max force / actual force = factor of safety
180,955 / 20000 = 9.05
I sure that's the final answer!
Thanks for the reply, I thought that to work out the area of a circle which in this case is the bolt, the equation is ∏r^2? or are you saying I only need to square the radius first then times it by pi?
and no I assume there's no units as its a ratio
Homework Statement
Two overlapping metal plates are bolted together with 12 bolts. The diameter of each bolt is 8mm. If the ultimate shear stress of the bolt material is 300MPa determine what factor of safety applies if the total force to be carries by the joint is 20kN.
Homework...