1.What is the diameter of a circular concrete column needed to support a load of 300,000 pounds with a factor of safety of 2? Round the diameter up to the whole inch. The concrete ultimate strength is 3000 lb/in^2.
2.A wrought-iron rod 2 inches in diameter sustains a load of 50,000 pounds. what is its tensile stress? if its ultimate strength is 60,000 lbs/in^2 find its factor of safety
3.Show that if an elastic, cylindrical soil is confined in the lateral directions, the costained elastic modulus is E(c) = E'(1-v')/(1+v')(1-2v') where E' = Youngs's modulus and v' is Poisson's ration for drained soil.