Consider a plane rectangular surface beneath a surface of water at an angle of 60 degrees from the surface. the width of the rectangle is 7.5 cm and the length of the rectangle is 10 cm. the lower borderline of the rectangle is parallel to the surface and 14.6 cm vertically below it. the upper borderline of the rectangle is parallel to the surface and 6.0 cm vertically below it. determine the force on the rectangular surface, the depth of the centroid of the surface, and the depth of the center of pressure of the surface.