A 3-in. Schedule 40 steel pipe is 5000 ft long and carries a lubricating oil between two points A and B such that the Reynolds number is 800. Point B is 20 ft higher that A. The oil has a specific gravity of 0.90 and a dynamic viscocity of 0.00040 lb-s/ft. If the pressure at A is 50 psig, calculate the pressure at B.