If a pressure tank is 100% full then the analog signal on a…

If a pressure tank is 100% full then the analog signal on a gauge reads 20psi.  If the tank is 0% full then the analog signal reads 2psi.  Assuming that the gauge psi scales linearly, how full is the tank if the gauge is signaling psi?  Give your answer to the nearest whole percent.

use the formula n = p + h – f, where n is the desired nozzle…

use the formula n = p + h – f, where n is the desired nozzle pressure in psi, p is the engine (pump) pressure in psi, h is the head gain or loss in psi, and f is the friction loss in psi.  For h, use a positive value of 0.5psi/foot if the head is adding pressure to the hose (nozzle downhill from pump) or a negative 0.5psi/foot if the head is subtracting pressure from the hose (nozzle uphill from pump). For f, use 5psi for the friction loss generated by each fitting in the line. A progressive, 6 length hose lay has five fittings connecting the hoses together.  The nozzle outlet is feet below the engine.  If the desired nozzle pressure is , at what pressure does the engine need to perform?