(10 points) A trapezoidal channel with a 2-foot depth of flow and 4% slope is to be lined with riprap on the bed and sidewalls for stabilization. a. What size riprap do you estimate is needed for the bed of the channel? b. What size riprap is needed for the sidewalls if the tractive force ratio is 0.5? c. Using the GSWCC's Table 6-39.3 - Determination of Rock Size For Stone Center Waterway below, what size riprap should be used? How close are the two methods?