A sinusoidal wave travels along a string. The time for a particular point to move from maximum displacement to zero is 0.15 s. What are the (a) period and (b) frequency

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.