You are gliding across a frictionless lake in a boat. If your mass is 80 Kg and the boat’s mass is 250 Kg, what force must the wind blow to make you accelerate at a rate of 0.30 m/s2?

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.