Question 1 4
An object is located 90 m in front of a lens. An image is produced 40 m away from the
lens. What is the focal length of the lens?
O 15.3 m
0.025 m
O 27.7 m
O .011 m

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.