Question

4 A cylindrical water-storage tank has a height of 7.7 m and a radius of 6.3 m. The storage tank is full of water but is vented to the atmosphere. The bottom of the tank is 32 m off the ground. A 11 cm diameter pipe runs vertically down from the tank and goes 1.8 m underground before turning horizontal. The water flow in the horizontal pipe is 72 L/s. MPLE I NOIES | IMAGES İ Discuss | | uNITS | | STATS | HELP」 Part Description Answer Chk History What is the water pressure (gauge) in the horizontal pipe underground? include units with answer) 10 pts. 2 20% A. # tries: O Show Details Forman Chack Hints: 1.1 How fast does the water level in the tank drop? (include units with answer) 10 pts·110% | # tries: 0 | Show Details | B. Rick Barnes drills a 6.3 mm dlameter hole near the bottom of the tank, How fast does the water shoot out? include units with answer) 10pts, 110 C. # tries: O! Show Details) Hints: 2.0 What volume flow of water is lost out the hole? include units with answer) 10 pts, 110% D. # tries; Show Details Hints: 10

Answer 1

Q = Av implies 72 times 10^-3 m^3/s = (pi 0.11^2/4) v v = 7.576 m/s Using Bernoulli's Equation P + rho gh + rho v^2/2 = Constant P_atm + (1000) (9.8) (7.7 + 32) + 0 = P + (1000) (9.8) (-1.8) + (1000) (7.576^2)/2 Delta P = P - P_atm = 3.78 times 10^5 Pa P_gauge = Delta P = 3.78 times 10^5 Pa Or 3.73 atm (b) Delta h_v = Q/A = (72 times 10^-2 m^2/s)/pi (6.3^2) = 0.58 times 10^-3 m/s Ans: 0.58 mm/s (c) P_atm + (1000) (5.8) (7.7) + 0 = P_atm + 0 + (1000) v^2/2 v = 12.3 m/s (d) Q = Av = (pi) (0.0063/2)^2 (12.3) = 0.38 times 10^-3 m^2/s Or 0.38 L/s