A bridge across a river is supported by a semielliptical arch with diameter (length of the major axis) of 1250 feet. The surface of the river lies on the major axis, and the center of the arch rises 175 feet above the river's surface. A horizontal roadway is 3 feet above the center of the arch. Find the vertical distance from the roadway to a point on the arch that is 600 feet (horizontally) from the center.