A farm water sprinkler is dead headed .the pipe raduis is 4 inches. The hight of the water 20 ft. the kinemitcs viscosity of the air is 1.4x10-5.air density 1.23kg/m3. water density 1000 kg/m3. What is the averge stress when the pressure drop is 38 psi over the entier lenght of the pipe?