Water Resources and Environmental Engineering — Quiz 10

Questions in this quiz (10)

1. Two tanks are connected by a $$9{,}000$$-ft length of $$12$$-in-I. D. PVC pipe. The Hazen-Williams coefficient is $$150$$. Water at $$60^\circ\mathrm{F}$$ flows through the pipe at a velocity of $$10$$ ft/sec. The tanks are open to the atmosphere. Entrance, exit, and minor losses are negligible. Determine the difference in water surface elevation between the two tanks.

   • 81
   • 167
   • 181
   • 447

2. For the apparatus shown in the figure, the volume of water collected at the outlet during a time interval of $$40$$ min is $$5\ \mathrm{cm^3}$$. The locations $$A$$, $$B$$, $$C$$, and $$D$$ are marked with their elevations in cm with respect to a common datum. Assume that reservoirs $$A$$ and $$D$$ have constant surface elevation. Determine the permeability of the soil in $$\mathrm{cm/h}$$.

   • 3.91 cm/h
   • 2.57 cm/h
   • 1.12 cm/h
   • 0.17 cm/h

3. Consider the NRCS rainfall-runoff method. An area in a drainage basin has its curve number $$CN$$ of $$100$$. Which statement about the soil in the area is true?

   • The soil is either saturated or impervious.
   • The soil is dry to the wilting point.
   • The soil can fully pass thru No. 100 sieve.
   • The soil is fully covered with grass.

4. A hydraulic jump occurs in an open channel where the upstream Froude number is $$3.96$$ and the upstream depth is $$0.65$$ m. Determine the height of the hydraulic jump.

   • 0.9 m
   • 2.7 m
   • 3.0 m
   • 1.35 m

5. A fire hydrant has a rated capacity of $$1235$$ gpm at $$20$$ psi. A field test shows that the static pressure of the hydrant's water distribution system is $$90$$ psi, and the residual pressure is $$45$$ psi. Determine the test flow.

   • 250 gpm
   • 620 gpm
   • 970 gpm
   • 1000 gpm

6. An aquifer has a thickness of $$52$$ ft and a transmissivity of $$650\ \mathrm{ft^2/day}$$. Determine the hydraulic conductivity of the aquifer.

   • 2.5 ft/day
   • 6.3 ft/day
   • 12.5 ft/day
   • 33 ft/day

7. Estimate the head loss in feet and the pressure loss in psi due to friction for a cast iron pipe with nominal diameter of $$8$$ in, transporting water at a flow rate of $$3$$ cfs over a distance of $$2450$$ ft. Use Hazen-Williams roughness coefficient $$C=100$$.

   • 126 ft and 54 psi
   • 118 ft and 54 psi
   • 118 ft and 134 psi
   • 126 ft and 134 psi

8. A $$53$$-acre watershed with curve number $$79$$ receives $$122$$ mm of precipitation. Calculate the maximum basin retention in inches.

   • 3.25
   • 2.99
   • 1.75
   • 2.65

9. A groundwater well has a specific capacity of $$15$$ gallons per minute per foot of drawdown and a pumping rate of $$250$$ gallons per minute. Determine the well drawdown.

   • 10 feet
   • 15 feet
   • 16.67 feet
   • 25 feet

10. Calculate the drawdown in a well after $$24$$ hours of continuous pumping at a rate of $$15$$ liters per second. The specific capacity of the well is $$0.0025$$ liters per second per meter of drawdown.

    • 2000 m
    • 3500 m
    • 4467 m
    • 6000 m