Question

Water at a pressure of 3.30 atm at street level flows into an office building at a speed of 0.70 m/s through a pipe 6.40 cm in diameter. The pipes taper down to 2.40 cm in diameter by the top floor, 28.0 m above. Calculate the water pressure in such a pipe on the top floor.
Your submitted answer is : 36289.7 Pa

Answer 1

Given:

gauge pressure p1 = 3.30 atm   (1 atm = 1.05*10^5 pascal)

= 3.30*1.05*10^5

= 3.46*10^5 pascal

speed v1 = 0.70 m/s

diameter of the pipe d1 = 6.4*10^-2 m

diameter of the pipe d2 = 2.4*10^-2 m

height of the pipe h = 28 m

From Bernoulli's equation of fluids

p2 = P1+ρgh

where ρ is the density of the water

p2 = 3.46*10^5+(0.9*10^3*9.8*28)

= 5.93*10^5 pascal