Two cars are driving towards an intersection from perpendicular directions. The first car's velocity is 222 meters per second and the second car's velocity is 999 meters per second. At a certain instant, the first car is 888 meters from the intersection and the second car is 666 meters from the intersection. What is the rate of change of the distance between the cars at that instant (in meters per second)

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.