Question

The water level in a water tower is 45 m above the ground. What is the gauge pressure of the water at a faucet that is 20 m above the ground?

Answer 1

Ppump=68600Pa

Explanation:
We understand that the sum of the pressures in the tank and the pump is equal to that of the Nozzle,
Ptank+Ppump=Pnozzle
For the pressure we also know that it is given by
P=Pgh
So
Ppump=pg(h2-h1)
Ppump=1000*9.8(27-20)
Ppump=68600Pa