Cooling water is fed by gravity from an open storage tank where the water level is 20 ft above the ground through 100 ft of 1 ½ inch ID steel pipe (light rust), to a heat exchanger at ground level. If the pressure entering the heat exchanger must be 5 psig for it to operate properly:

(a) Ignoring the kinetic energy change, what is the water flow rate through the pipe?
(b) After ignoring the kinetic energy, validate whether this was a good assumption.