For a preliminary vertical alignment of a roadway, the straight tangent sections are established as follows:
Station 0 + 00, tangent elevation = 73.00
Station 9 + 50, tangent elevation = 49.25
Station 22 + 25, tangent elevation = 93.00
Station 29 + 00, tangent elevation = 105.00
Determine the gradient of each tangent and the elevation at 500-ft intervals along the tangents