A long, solid cylinder of radius 2 ft hinged at point A is used as an automatic gate, as shown in Fig. P3-61E. When the water level reaches 15 ft, the cylindrical gate opens by turning about the hinge at point A. Determine
(a) the hydrostatic force acting on the cylinder and its line of action when the gate opens and
(b) the weight of the cylinder per ft length of the cylinder.