With the ability to measure the motion of land masses, continental drift has become an established fact. The North American and European continents are drifting apart at a rate of about 3 cm/yr. At this rate how long will it take them to drift 750 km further apart than at present?

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.