Water at a gauge pressure of 3.8 atm at street level flows into an office building at a speed of 0.45 m/s through a pipe 4.2 cm in diameter. The pipe tapers down to 2.6 cm in diameter by the top floor, 20 m above (Fig. 10-53), wher the faucet has been left open. Calculate the flow velocity and the gauge pressure in such a pipe on the top floor. Assume no branch pipes and ignore viscosity.