Suppose the axial member has a circular cross section with a diameter of db = 10 cm at section b and a diameter of dd = 5 cm at section d. what is the average normal stress in the section with the maximum magnitude stress? express your answer to three significant figures with the appropriate units.

A5 foot by 5 foot box culvert is buried 6 feet beneath the surface of the ground. a crosssection of this very long culvert (into and out of the page) is illustrated below. assume that the soil in which the culvert is buried has the following properties: jt = 120 pcf, w = 12%, ko = 0.50, ka = 0.33, and kp = 3.00. calculate the total horizontal force per unit length of culvert (fh) felt on one of the vertical faces of the culvert.