Forces contribute to the net force on a car rolling down a ramp.
a. which force supports the car’s weight?
b. which force accelerates the car down the ramp?
c. which force acts against the motion of the car?

Use the profile illustrated for problem (1). assume that the layer of silty sand fill (sm) is placed over the entire site. estimate the thickness of the fill (h - in feet) that will cause the effective vertical stress at the center of the clay layer to increase by 517.5 pounds per square foot.