Problem 13.54 Water at a gauge pressure of 3,8 atm at street level flows into an
ID: 1606291 • Letter: P
Question
Problem 13.54 Water at a gauge pressure of 3,8 atm at street level flows into an office building at a speed of 0.69 m/s through a pipe 5.5 cm in diameter. The pipe tapers down to 2.5 cm in diameter by the top floor, 18 m above, where the faucet has been left open. (Figure 1) Figure 1 of 1 Faucet 18 m P 38 atm Part A Calculate the flow velocity in the pipe on the top floor. Assume no branch pipes and ignore viscosity. Express your answer using two significant figures. v 2.2 m/S Submit My Answers Give Up incorrect; Try Again: 5 attempts remaining Part B Calculate the gauge pressure in the pipe on the top floor. Assume no branch pipes and ignore viscosity. Express your answer using two significant figures. Pa
Explanation / Answer
(A) volume flow rate will be same throughout the pipe.
A1 v1 = A2 v2
(pi d1^2 / 4) v1 = (pi d2^2 / 4) v2
5.5^2 x 0.69 = 2.5^2 v2
v2 = 3.34 m/s ............Ans
(B) Applying bernoulli's equation,
P + rho g h + rho v^2 /2 = constant
(3.8 x 101325 Pa) + (1000 x 9.8 x 0) + (1000 x 0.69^2 /2) = P + (1000 x 9.8 x 18) + (1000 x 3.34^2 /2)
385035 + 238.05 = P + 176400 + 5577.8
P = 203295.25 Pa .......Ans