Hydraulics: Water is flowing through a pipe

Water is flowing through a pipe having diameter 300mm and 200mm at the bottom and upper end respectively. The intensity of pressure at the bottom end is 24.525 N/cm^2 and the pressure at the upper end is 9.81 N/cm^2. Determine the difference of elevation of the two ends if the rate of flow is 40 liters/sec. Assume no head loss.