A pipe of diameter 1 m is at the top of a 20 m tall hill. Water flows through the pipe with a velocity of v = 5 m/s for a distance of 10 m before the pipe constricts to a radius of .5 m. The water then flows for another 8 m before the pipe bends downwards and travels to the ground. Find the fluid velocity at the ground level. What is the pressure difference between the lower and upper parts of the pipe?